1
|
Le ND, Bouteyre P, Kheir-Aldine A, Dubois F, Cueff S, Berguiga L, Letartre X, Viktorovitch P, Benyattou T, Nguyen HS. Super Bound States in the Continuum on a Photonic Flatband: Concept, Experimental Realization, and Optical Trapping Demonstration. PHYSICAL REVIEW LETTERS 2024; 132:173802. [PMID: 38728718 DOI: 10.1103/physrevlett.132.173802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 03/18/2024] [Indexed: 05/12/2024]
Abstract
In this Letter, we theoretically propose and experimentally demonstrate the formation of a super bound state in a continuum (BIC) on a photonic crystal flat band. This unique state simultaneously exhibits an enhanced quality factor and near-zero group velocity across an extended region of the Brillouin zone. It is achieved at the topological transition when a symmetry-protected BIC pinned at k=0 merges with two Friedrich-Wintgen quasi-BICs, which arise from the destructive interference between lossy photonic modes of opposite symmetries. As a proof of concept, we employ the ultraflat super BIC to demonstrate three-dimensional optical trapping of individual particles. Our findings present a novel approach to engineering both the real and imaginary components of photonic states on a subwavelength scale for innovative optoelectronic devices.
Collapse
Affiliation(s)
- Ngoc Duc Le
- Univ Lyon, ECL, INSA Lyon, CNRS, UCBL, CPE Lyon, INL UMR 5270, 69130 Écully, France
- Université Paris-Saclay, CNRS, CEA, Institut de Physique Théorique, 91191 Gif-sur-Yvette, France
| | - Paul Bouteyre
- Univ Lyon, ECL, INSA Lyon, CNRS, UCBL, CPE Lyon, INL UMR 5270, 69130 Écully, France
- Department of Physics and Astronomy, University of Sheffield, S3 7RH, Sheffield, United Kingdom
| | - Ali Kheir-Aldine
- Univ Lyon, ECL, INSA Lyon, CNRS, UCBL, CPE Lyon, INL UMR 5270, 69130 Écully, France
| | - Florian Dubois
- Univ Lyon, ECL, INSA Lyon, CNRS, UCBL, CPE Lyon, INL UMR 5270, 69130 Écully, France
- Silicon Austria Labs GmbH (SAL), 9524 Villach, Austria
| | - Sébastien Cueff
- Univ Lyon, ECL, INSA Lyon, CNRS, UCBL, CPE Lyon, INL UMR 5270, 69130 Écully, France
| | - Lotfi Berguiga
- Univ Lyon, ECL, INSA Lyon, CNRS, UCBL, CPE Lyon, INL UMR 5270, 69130 Écully, France
| | - Xavier Letartre
- Univ Lyon, ECL, INSA Lyon, CNRS, UCBL, CPE Lyon, INL UMR 5270, 69130 Écully, France
| | - Pierre Viktorovitch
- Univ Lyon, ECL, INSA Lyon, CNRS, UCBL, CPE Lyon, INL UMR 5270, 69130 Écully, France
| | - Taha Benyattou
- Univ Lyon, ECL, INSA Lyon, CNRS, UCBL, CPE Lyon, INL UMR 5270, 69130 Écully, France
| | - Hai Son Nguyen
- Univ Lyon, ECL, INSA Lyon, CNRS, UCBL, CPE Lyon, INL UMR 5270, 69130 Écully, France
- Institut Universitaire de France (IUF), 75231 Paris, France
| |
Collapse
|
2
|
Huo P, Chen W, Zhang Z, Zhang Y, Liu M, Lin P, Zhang H, Chen Z, Lezec H, Zhu W, Agrawal A, Peng C, Lu Y, Xu T. Observation of spatiotemporal optical vortices enabled by symmetry-breaking slanted nanograting. Nat Commun 2024; 15:3055. [PMID: 38594345 PMCID: PMC11003997 DOI: 10.1038/s41467-024-47475-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 04/02/2024] [Indexed: 04/11/2024] Open
Abstract
Providing additional degrees of freedom to manipulate light, spatiotemporal optical vortex (STOV) beams carrying transverse orbital angular momentum are of fundamental importance for spatiotemporal control of light-matter interactions. Unfortunately, existing methods to generate STOV are plagued by various limitations such as inefficiency, bulkiness, and complexity. Here, we theoretically propose and experimentally demonstrate a microscale singlet platform composed of a slanted nanograting to generate STOV. Leveraging the intrinsic topological singularity induced by C2 symmetry and z-mirror symmetry breaking of the slanted nanograting, STOV is generated through the Fourier transform of the spiral phase in the momentum-frequency space to the spatiotemporal domain. In experiments, we observe the space-time evolution of STOV carried by femtosecond pulses using a time-resolved interferometry technique and achieve a generation efficiency exceeding 40%. Our work sheds light on a compact and versatile platform for light pulse shaping, and paves the way towards a fully integrated system for spatiotemporal light manipulation.
Collapse
Affiliation(s)
- Pengcheng Huo
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, Nanjing University, Nanjing, 210093, China
| | - Wei Chen
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, Nanjing University, Nanjing, 210093, China
| | - Zixuan Zhang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, Frontiers Science Center for Nano-optoelectronics, Peking University, 100871, Beijing, China
| | - Yanzeng Zhang
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, Nanjing University, Nanjing, 210093, China
| | - Mingze Liu
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, Nanjing University, Nanjing, 210093, China
| | - Peicheng Lin
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, Nanjing University, Nanjing, 210093, China
| | - Hui Zhang
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, Nanjing University, Nanjing, 210093, China
| | - Zhaoxian Chen
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, Nanjing University, Nanjing, 210093, China
| | - Henri Lezec
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Wenqi Zhu
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
- Maryland NanoCenter, University of Maryland, College Park, MD, 20742, USA
| | - Amit Agrawal
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Chao Peng
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, Frontiers Science Center for Nano-optoelectronics, Peking University, 100871, Beijing, China.
| | - Yanqing Lu
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, Nanjing University, Nanjing, 210093, China.
| | - Ting Xu
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, Nanjing University, Nanjing, 210093, China.
| |
Collapse
|
3
|
Wang H, Zuo Y, Yin X, Chen Z, Zhang Z, Wang F, Hu Y, Zhang X, Peng C. Ultralow-loss optical interconnect enabled by topological unidirectional guided resonance. SCIENCE ADVANCES 2024; 10:eadn4372. [PMID: 38507487 PMCID: PMC10954227 DOI: 10.1126/sciadv.adn4372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 02/12/2024] [Indexed: 03/22/2024]
Abstract
Grating couplers that interconnect photonic chips to off-chip components are crucial for various optoelectronics applications. Despite numerous efforts in past decades, the existing grating couplers are still far from optimal in energy efficiency and thus hinder photonic integration toward a larger scale. Here, we propose a strategy to achieve ultralow-loss grating couplers by using unidirectional guided resonances (UGRs), suppressing the useless downward radiation with no mirror on the bottom. By engineering the dispersion and apodizing the geometry of grating, we experimentally realize a grating coupler with a record-low loss of -0.34 dB and 1-dB bandwidth exceeding 30 nm at the telecom wavelength of 1550 nm and further demonstrate an optic via with a loss of only -0.94 dB. Given that UGRs ubiquitously exist in a variety of grating geometries, our work sheds light on a systematic method to achieve energy-efficient optical interconnect and paves the way to large-scale photonic integration.
Collapse
Affiliation(s)
- Haoran Wang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics & Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Yi Zuo
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics & Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Xuefan Yin
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics & Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
- Department of Electronic Science and Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Zihao Chen
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics & Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Zixuan Zhang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics & Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Feifan Wang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics & Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Yuefeng Hu
- Peng Cheng Laboratory, Shenzhen 518055, China
- Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Xiaoyu Zhang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics & Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Chao Peng
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics & Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
- Peng Cheng Laboratory, Shenzhen 518055, China
| |
Collapse
|
4
|
Zhuang ZP, Zeng HL, Chen XD, He XT, Dong JW. Topological Nature of Radiation Asymmetry in Bilayer Metagratings. PHYSICAL REVIEW LETTERS 2024; 132:113801. [PMID: 38563935 DOI: 10.1103/physrevlett.132.113801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 02/13/2024] [Indexed: 04/04/2024]
Abstract
Manipulating radiation asymmetry of photonic structures is of particular interest in many photonic applications such as directional optical antenna, high efficiency on-chip lasers, and coherent light control. Here, we proposed a term of pseudopolarization to reveal the topological nature of radiation asymmetry in bilayer metagratings. Robust pseudopolarization vortex with an integer topological charge exists in P-symmetry metagrating, allowing for tunable directionality ranging from -1 to 1 in synthetic parameter space. When P-symmetry breaking, such vortex becomes pairs of C points due to the conservation law of charge, leading to the phase difference of radiation asymmetry from π/2 to 3π/2. Furthermore, topologically enabled coherent perfect absorption is robust with customized phase difference at will between two counterpropagating external light sources. This Letter can not only enrich the understanding of two particular topological photonic behaviors, i.e., bound state in the continuum and unidirectional guided resonance, but also provide a topological view on radiation asymmetry, opening an unexplored avenue for asymmetric light manipulation in on-chip laser, light-light switch, and quantum emitters.
Collapse
Affiliation(s)
- Ze-Peng Zhuang
- School of Physics and State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| | - Hao-Long Zeng
- School of Physics and State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| | - Xiao-Dong Chen
- School of Physics and State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| | - Xin-Tao He
- School of Physics and State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| | - Jian-Wen Dong
- School of Physics and State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China
| |
Collapse
|
5
|
Liu T, Bai K, Zhang Y, Wan D, Lai Y, Chan CT, Xiao M. Finite barrier bound state. LIGHT, SCIENCE & APPLICATIONS 2024; 13:69. [PMID: 38453882 PMCID: PMC10920789 DOI: 10.1038/s41377-024-01417-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/18/2024] [Accepted: 02/26/2024] [Indexed: 03/09/2024]
Abstract
A boundary mode localized on one side of a finite-size lattice can tunnel to the opposite side which results in unwanted couplings. Conventional wisdom tells that the tunneling probability decays exponentially with the size of the system which thus requires many lattice sites before eventually becoming negligibly small. Here we show that the tunneling probability for some boundary modes can apparently vanish at specific wavevectors. Thus, similar to bound states in the continuum, a boundary mode can be completely trapped within very few lattice sites where the bulk bandgap is not even well-defined. More intriguingly, the number of trapped states equals the number of lattice sites along the normal direction of the boundary. We provide two configurations and validate the existence of this peculiar finite barrier-bound state experimentally in a dielectric photonic crystal at microwave frequencies. Our work offers extreme flexibility in tuning the coupling between localized states and channels as well as a new mechanism that facilitates unprecedented manipulation of light.
Collapse
Affiliation(s)
- Tao Liu
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, 430072, Wuhan, China
| | - Kai Bai
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, 430072, Wuhan, China
| | - Yicheng Zhang
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, 430072, Wuhan, China
| | - Duanduan Wan
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, 430072, Wuhan, China.
| | - Yun Lai
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, 210093, Nanjing, China
| | - C T Chan
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, 999077, Hong Kong, China
| | - Meng Xiao
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, 430072, Wuhan, China.
- Wuhan Institute of Quantum Technology, 430206, Wuhan, China.
| |
Collapse
|
6
|
Shumilin AV, Shamirzaev TS, Smirnov DS. Spin Light Emitting Diode Based on Exciton Fine Structure Tuning in Quantum Dots. PHYSICAL REVIEW LETTERS 2024; 132:076202. [PMID: 38427866 DOI: 10.1103/physrevlett.132.076202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 01/17/2024] [Indexed: 03/03/2024]
Abstract
We propose a concept of quantum dot based light emitting diode that produces circularly polarized light without magnetic contacts due to the hyperfine interaction at the crossing of the exciton levels in a weak magnetic field. The electroluminescence circular polarization degree can reach 100%. The concept is compatible with the micropillar cavities, which allows for the generation of single circularly polarized photons. Second order photon correlation function includes information about the nuclear spin dynamics in the quantum dot, and the nuclear spin state can be purified by the quantum measurement backaction.
Collapse
Affiliation(s)
- A V Shumilin
- Ioffe Institute, 194021 St. Petersburg, Russia
- Complex Matter Department, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - T S Shamirzaev
- Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - D S Smirnov
- Ioffe Institute, 194021 St. Petersburg, Russia
| |
Collapse
|
7
|
Ni X, Liu Y, Lou B, Zhang M, Hu EL, Fan S, Mazur E, Tang H. Three-Dimensional Reconfigurable Optical Singularities in Bilayer Photonic Crystals. PHYSICAL REVIEW LETTERS 2024; 132:073804. [PMID: 38427898 DOI: 10.1103/physrevlett.132.073804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 01/12/2024] [Indexed: 03/03/2024]
Abstract
Metasurfaces and photonic crystals have revolutionized classical and quantum manipulation of light and opened the door to studying various optical singularities related to phases and polarization states. However, traditional nanophotonic devices lack reconfigurability, hindering the dynamic switching and optimization of optical singularities. This paper delves into the underexplored concept of tunable bilayer photonic crystals (BPhCs), which offer rich interlayer coupling effects. Utilizing silicon nitride-based BPhCs, we demonstrate tunable bidirectional and unidirectional polarization singularities, along with spatiotemporal phase singularities. Leveraging these tunable singularities, we achieve dynamic modulation of bound-state-in-continuum states, unidirectional guided resonances, and both longitudinal and transverse orbital angular momentum. Our work paves the way for multidimensional control over polarization and phase, inspiring new directions in ultrafast optics, optoelectronics, and quantum optics.
Collapse
Affiliation(s)
- Xueqi Ni
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Yuan Liu
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Beicheng Lou
- Department of Applied Physics and Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
| | - Mingjie Zhang
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Evelyn L Hu
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Shanhui Fan
- Department of Applied Physics and Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
| | - Eric Mazur
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Haoning Tang
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| |
Collapse
|
8
|
Qian L, Zhang W, Sun H, Zhang X. Non-Abelian Topological Bound States in the Continuum. PHYSICAL REVIEW LETTERS 2024; 132:046601. [PMID: 38335357 DOI: 10.1103/physrevlett.132.046601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 01/03/2024] [Indexed: 02/12/2024]
Abstract
Bound states in the continuum (BICs), which are spatially localized states with energies lying in the continuum of extended modes, have been widely investigated in both quantum and classical systems. Recently, the combination of topological band theory with BICs has led to the creation of topological BICs that exhibit extraordinary robustness against disorder. However, the previously proposed topological BICs are only limited in systems with Abelian gauge fields. Whether non-Abelian gauge fields can induce topological BICs and how to experimentally explore these phenomena remains unresolved. Here, we report the theoretical and experimental realization of non-Abelian topological BICs, which are generated by the interplay between two inseparable pseudospins and can coexist in each pseudospin subspace. This unique characteristic necessitates non-Abelian couplings that lack any Abelian counterparts. Furthermore, the non-Abelian couplings can also offer a new avenue for constructing topological subspace-induced BICs at bulk dislocations. Those exotic phenomena are observed by non-Abelian topolectrical circuits. Our results establish the connection between topological BICs and non-Abelian gauge fields, and serve as the catalyst for future investigations on non-Abelian topological BICs across different platforms.
Collapse
Affiliation(s)
- Long Qian
- Key Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Weixuan Zhang
- Key Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Houjuan Sun
- Beijing Key Laboratory of Millimeter wave and Terahertz Techniques, School of Information and Electronics, Beijing Institute of Technology, Beijing 100081, China
| | - Xiangdong Zhang
- Key Laboratory of advanced optoelectronic quantum architecture and measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, China
| |
Collapse
|
9
|
Chen Z, Shao L, Mao L, Yang R, Shi X, Jin M, Bai N, Sun X. Rigorous coupled-wave analysis of unilateral Smith-Purcell radiation from asymmetric resonators. APPLIED OPTICS 2024; 63:708-713. [PMID: 38294383 DOI: 10.1364/ao.514085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 12/11/2023] [Indexed: 02/01/2024]
Abstract
The Smith-Purcell radiation produced by electrons moving closely to a grating can be enhanced by resonances. Here, we show a method to manipulate the directionality of the resonance-enhanced radiation. Using the rigorous coupled-wave analysis method, we compare the radiation from symmetric and asymmetric gratings, showing that the enhanced Smith-Purcell radiation can become unilateral with a perturbation that breaks the structural symmetry. Our work provides an effective method for frequency-domain calculation of Smith-Purcell radiation and also an approach to realize more efficient use of the radiation.
Collapse
|
10
|
Zhang Y, Liu X, Zhao R, Li J. Unidirectional asymmetry transmission based on quasi-accidental bound states in the continuum. Phys Chem Chem Phys 2023; 25:31869-31873. [PMID: 37970959 DOI: 10.1039/d3cp03265e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The unidirectional asymmetry transmission is demonstrated based on quasi-accidental bound states in the continuum by a one-dimensional chiral photonic crystal slab (CPhCs) composed of tilted silicon nano-pillars. The chirality breaks symmetries on the far field polarization and radiation Q-factor between the upward and downward radiation channels. Accordingly, the CPhCs only supports the unidirectional maximal asymmetry transmission at fixed incident and conical angles. The numerical simulation indicates that the CPhCs obtains a circular dichroism of 0.99 and Q-factor of 753.7 at λ = 1.565 μm. In addition, the handedness of polarization is also effectively converted between the incidence and transmission, and the handedness depends on the incident direction and conical angle. Our scheme provides a feasible route for applications in manipulating polarization and chiral sensing.
Collapse
Affiliation(s)
- Yingjie Zhang
- School of Physics, Harbin Institute of Technology, Harbin 150001, China.
| | - Xingguang Liu
- School of Physics, Harbin Institute of Technology, Harbin 150001, China.
- Research Station for Electronic Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Rui Zhao
- School of Physics, Harbin Institute of Technology, Harbin 150001, China.
| | - Junqing Li
- School of Physics, Harbin Institute of Technology, Harbin 150001, China.
| |
Collapse
|
11
|
Xu W, Hong Q, Peng J, Liu P, Yang B, Guo C, Zhu Z. Reflectionless graphene perfect absorber based on parity symmetric unidirectional guided resonance. OPTICS LETTERS 2023; 48:5963-5966. [PMID: 37966763 DOI: 10.1364/ol.506732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 10/21/2023] [Indexed: 11/16/2023]
Abstract
We propose a type of reflectionless graphene perfect absorber (GPA) in which the reflection channel is forbidden, while the transmission channel is open. Peak absorption of 99.97% in the near-infrared is numerically demonstrated for monolayer graphene loaded on a one-dimensional silicon photonic crystal slab with rhomboid cross sections that supports parity symmetric unidirectional guided resonances (UGRs). Based on the proposed GPA, a transmissive optical modulator with a modulation depth of about 28 dB and an insertion loss of 0.31 dB by varying the Fermi energy level graphene from 0.3 eV to 0.7 eV is numerically presented. Remarkably, the design strategy can be straightforwardly applied to other two-dimensional (2D) materials. Our study may find promising applications in 2D material-based optical modulators and filters.
Collapse
|
12
|
Liu W, Yan B, Jiang X. High performance sensor based on phase difference induced quasi-BIC and Fermi energy. OPTICS LETTERS 2023; 48:6012-6014. [PMID: 37966776 DOI: 10.1364/ol.507991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 10/24/2023] [Indexed: 11/16/2023]
Abstract
We propose a dielectric corrugated structure surrounded by two monolayer graphene and find that the structure supports bound states in the continuum (BIC). By introducing a phase difference between the upper and lower surface of dielectric grating, the symmetry of the structure is broken, and the BIC turns into quasi-BIC. In addition, we find that the Fermi energy of graphene strongly affect the spectral line. By controlling phase difference and Fermi energy of graphene, the ultrahigh Q-factor can be achieved. Finally, introducing a sensing medium at the incident side, the high performance sensor is realized.
Collapse
|
13
|
Zhong H, He T, Meng Y, Xiao Q. Photonic Bound States in the Continuum in Nanostructures. MATERIALS (BASEL, SWITZERLAND) 2023; 16:7112. [PMID: 38005042 PMCID: PMC10672634 DOI: 10.3390/ma16227112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/02/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023]
Abstract
Bound states in the continuum (BIC) have garnered considerable attention recently for their unique capacity to confine electromagnetic waves within an open or non-Hermitian system. Utilizing a variety of light confinement mechanisms, nanostructures can achieve ultra-high quality factors and intense field localization with BIC, offering advantages such as long-living resonance modes, adaptable light control, and enhanced light-matter interactions, paving the way for innovative developments in photonics. This review outlines novel functionality and performance enhancements by synergizing optical BIC with diverse nanostructures, delivering an in-depth analysis of BIC designs in gratings, photonic crystals, waveguides, and metasurfaces. Additionally, we showcase the latest advancements of BIC in 2D material platforms and suggest potential trajectories for future research.
Collapse
Affiliation(s)
| | | | | | - Qirong Xiao
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China; (H.Z.); (T.H.); (Y.M.)
| |
Collapse
|
14
|
Xu W, Hong Q, Liu P, Peng J, Yang B, Zhang J, Zhu Z. High quality factor unidirectional guided resonances of a silicon-on-lithium niobate photonic crystal slab for a tunable Gires-Tournois interferometer. OPTICS LETTERS 2023; 48:4761-4764. [PMID: 37707896 DOI: 10.1364/ol.498936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/21/2023] [Indexed: 09/15/2023]
Abstract
High quality (Q) factor, tunable unidirectional guided resonances (UGRs) based on a silicon-on-lithium niobate (Si-on-LN) photonic crystal (PhC) slab are proposed and numerically investigated. The Q factors of UGRs decay quadratically with respect to the distance from the Γ point to the wave vector along the Γ-X direction, and high Q factor UGRs are obtained by moving UGR close to the Γ point. Also, a Gires-Tournois interferometer (GTI) based on a UGR with a Q factor of 9465 is numerically demonstrated, which produces a maximum group delay of 30 ps around 1.55 μm with unitary reflectance. The group delay and operation wavelengths of the GTI can be adjusted effectively by tuning the refractive index of lithium niobate (LN) and the periods of the silicon bars. Our study may find applications in PhC surface-emitting lasers, dispersion compensation, and compression of light pulses.
Collapse
|
15
|
Rong K, Duan X, Wang B, Reichenberg D, Cohen A, Liu CL, Mohapatra PK, Patsha A, Gorovoy V, Mukherjee S, Kleiner V, Ismach A, Koren E, Hasman E. Spin-valley Rashba monolayer laser. NATURE MATERIALS 2023; 22:1085-1093. [PMID: 37414946 DOI: 10.1038/s41563-023-01603-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 06/07/2023] [Indexed: 07/08/2023]
Abstract
Direct-bandgap transition metal dichalcogenide monolayers are appealing candidates to construct atomic-scale spin-optical light sources owing to their valley-contrasting optical selection rules. Here we report on a spin-optical monolayer laser by incorporating a WS2 monolayer into a heterostructure microcavity supporting high-Q photonic spin-valley resonances. Inspired by the creation of valley pseudo-spins in monolayers, the spin-valley modes are generated from a photonic Rashba-type spin splitting of a bound state in the continuum, which gives rise to opposite spin-polarized ±K valleys due to emergent photonic spin-orbit interaction under inversion symmetry breaking. The Rashba monolayer laser shows intrinsic spin polarizations, high spatial and temporal coherence, and inherent symmetry-enabled robustness features, enabling valley coherence in the WS2 monolayer upon arbitrary pump polarizations at room temperature. Our monolayer-integrated spin-valley microcavities open avenues for further classical and non-classical coherent spin-optical light sources exploring both electron and photon spins.
Collapse
Affiliation(s)
- Kexiu Rong
- Atomic-Scale Photonics Laboratory, Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa, Israel
| | - Xiaoyang Duan
- Atomic-Scale Photonics Laboratory, Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa, Israel
| | - Bo Wang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China
| | - Dror Reichenberg
- Atomic-Scale Photonics Laboratory, Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa, Israel
| | - Assael Cohen
- Department of Materials Science and Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Chieh-Li Liu
- Atomic-Scale Photonics Laboratory, Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa, Israel
| | - Pranab K Mohapatra
- Department of Materials Science and Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Avinash Patsha
- Department of Materials Science and Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Vladi Gorovoy
- Atomic-Scale Photonics Laboratory, Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa, Israel
| | - Subhrajit Mukherjee
- Faculty of Materials Science and Engineering, Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion-Israel Institute of Technology, Haifa, Israel
| | - Vladimir Kleiner
- Atomic-Scale Photonics Laboratory, Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa, Israel
| | - Ariel Ismach
- Department of Materials Science and Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Elad Koren
- Faculty of Materials Science and Engineering, Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion-Israel Institute of Technology, Haifa, Israel
| | - Erez Hasman
- Atomic-Scale Photonics Laboratory, Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa, Israel.
| |
Collapse
|
16
|
Zhang Z, Xu C, Liu C, Lang M, Zhang Y, Li M, Lu W, Chen Z, Wang C, Wang S, Li X. Dual Control of Enhanced Quasi-Bound States in the Continuum Emission from Resonant c-Si Metasurfaces. NANO LETTERS 2023; 23:7584-7592. [PMID: 37539848 DOI: 10.1021/acs.nanolett.3c02148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
Optical bound states in the continuum (BICs) offer strong interactions with quantum emitters and have been extensively studied for manipulating spontaneous emission, lasing, and polariton Bose-Einstein condensation. However, the out-coupling efficiency of quasi-BIC emission, crucial for practical light-emitting devices, has received less attention. Here, we report an adaptable approach for enhancing quasi-BIC emission from a resonant monocrystalline silicon (c-Si) metasurface through lattice and multipolar engineering. We identify dual-BICs originating from electric quadrupoles (EQ) and out-of-plane magnetic dipoles, with EQ quasi-BICs exhibiting concentrated near-fields near the c-Si nanodisks. The enhanced fractional radiative local density of states of EQ quasi-BICs overlaps spatially with the emitters, promoting efficient out-coupling. Furthermore, coupling the EQ quasi-BICs with Rayleigh anomalies enhances directional emission intensity, and we observe inherent opposite topological charges in the multipolarly controlled dual-BICs. These findings provide valuable insights for developing efficient nanophotonic devices based on quasi-BICs.
Collapse
Affiliation(s)
- Zhenghe Zhang
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| | - Chaojie Xu
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials Devices, Soochow University, Suzhou 215123, China
| | - Chen Liu
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| | - Man Lang
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| | - Yuehao Zhang
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| | - Minghao Li
- Department of Physics and Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Wanli Lu
- School of Materials Science and Physics, China University of Mining and Technology, Xuzhou 221116, China
| | - Zefeng Chen
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| | - Chinhua Wang
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| | - Shaojun Wang
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| | - Xiaofeng Li
- School of Optoelectronic Science and Engineering & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China
- Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province & Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006, China
| |
Collapse
|
17
|
An Y, Fu T, Guo C, Pei J, Ouyang Z. Two Individual Super-Bound State Modes within Band Gap with Ultra-High Q Factor for Potential Sensing Applications in the Terahertz Wave Band. SENSORS (BASEL, SWITZERLAND) 2023; 23:6737. [PMID: 37571521 PMCID: PMC10422254 DOI: 10.3390/s23156737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/25/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023]
Abstract
Bound states in the continuum (BICs) garnered significant research interest in the field of sensors due to their exceptionally high-quality factors. However, the wide-band continuum in BICs are noise to the bound states, and it is difficult to control and filter. Therefore, we constructed a top-bottom symmetric cavity containing three high permittivity rectangular columns. The cavity supports a symmetry-protected (SP) superbound state (SBS) mode and an accidental (AC) SBS mode within the bandgap. With a period size of 5 × 15, the bandgap effectively filters out the continuum, allowing only the bound states to exist. This configuration enabled us to achieve a high signal-to-noise ratio and a wide free-spectral-range. The AC SBS and the SP SBS can be converted into quasi-SBS by adjusting different parameters. Consequently, the cavity can function as a single-band sensor or a dual-band sensor. The achieved bulk sensitivity was 38 µm/RIU in terahertz wave band, and a record-high FOM reached 2.8 × 108 RIU-1. The effect of fabrication error on the performance for sensor application was also discussed, showing that the application was feasible. Moreover, for experimental realization, a 3D schematic was presented. These achievements pave the way for compact, high-sensitivity biosensing, multi-wavelength sensing, and other promising applications.
Collapse
Affiliation(s)
- Yinbing An
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China (C.G.)
- THz Technical Research Center, Shenzhen Key Laboratory of Micro-Nano Photonic Information Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Tao Fu
- Guangxi Key Laboratory of Precision Navigation Technology and Application, Guilin University of Electronic Technology, Guilin 541004, China
| | - Chunyu Guo
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China (C.G.)
| | - Jihong Pei
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, China;
| | - Zhengbiao Ouyang
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China (C.G.)
- THz Technical Research Center, Shenzhen Key Laboratory of Micro-Nano Photonic Information Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| |
Collapse
|
18
|
Tang H, Lou B, Du F, Zhang M, Ni X, Xu W, Jin R, Fan S, Mazur E. Experimental probe of twist angle-dependent band structure of on-chip optical bilayer photonic crystal. SCIENCE ADVANCES 2023; 9:eadh8498. [PMID: 37436985 DOI: 10.1126/sciadv.adh8498] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 06/13/2023] [Indexed: 07/14/2023]
Abstract
Recently, twisted bilayer photonic materials have been extensively used for creating and studying photonic tunability through interlayer couplings. While twisted bilayer photonic materials have been experimentally demonstrated in microwave regimes, a robust platform for experimentally measuring optical frequencies has been elusive. Here, we demonstrate the first on-chip optical twisted bilayer photonic crystal with twist angle-tunable dispersion and great simulation-experiment agreement. Our results reveal a highly tunable band structure of twisted bilayer photonic crystals due to moiré scattering. This work opens the door to realizing unconventional twisted bilayer properties and novel applications in optical frequency regimes.
Collapse
Affiliation(s)
- Haoning Tang
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Beicheng Lou
- Department of Applied Physics and Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA
| | - Fan Du
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Mingjie Zhang
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Xueqi Ni
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Weijie Xu
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Rebekah Jin
- University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Shanhui Fan
- Department of Applied Physics and Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA
| | - Eric Mazur
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| |
Collapse
|
19
|
Jiang Q, Hu P, Wang J, Han D, Zi J. General Bound States in the Continuum in Momentum Space. PHYSICAL REVIEW LETTERS 2023; 131:013801. [PMID: 37478422 DOI: 10.1103/physrevlett.131.013801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 06/08/2023] [Indexed: 07/23/2023]
Abstract
Polarization singularities including bound states in the continuum (BICs) and circularly polarized states have provided promising opportunities in the manipulation of light waves. Previous studies show that BICs in photonic crystal slabs are protected by C_{2}T symmetry and hence normally exist on the high-symmetry lines of momentum space. Here, we propose an approach based on graph theory to study these polarization singularities in momentum space, especially in the region off the high-symmetry lines. With a polarization graph, it is demonstrated for the first time that BICs can stably exist off the high-symmetry lines of momentum space for both one-dimensional and two-dimensional photonic crystal slabs. Furthermore, two kinds of interesting processes, including the merging involved with this newly found BICs both on and off the high-symmetry lines, are observed by changing the geometrical parameters of photonic crystal slabs while keeping their symmetry. Our findings provide a new perspective to explore polarization singularities in momentum space and render their further applications in light-matter interaction and light manipulation.
Collapse
Affiliation(s)
- Qiao Jiang
- College of Physics, Chongqing University, Chongqing 401331, China
- Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 401331, China
| | - Peng Hu
- College of Physics, Chongqing University, Chongqing 401331, China
| | - Jun Wang
- College of Physics, Chongqing University, Chongqing 401331, China
| | - Dezhuan Han
- College of Physics, Chongqing University, Chongqing 401331, China
| | - Jian Zi
- Department of Physics, Key Laboratory of Micro- and Nano-Photonic Structures (MOE), and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| |
Collapse
|
20
|
Han Y, Meng C, Pan H, Qian J, Rao Z, Zhu L, Gui Y, Hu CM, An Z. Bound chiral magnonic polariton states for ideal microwave isolation. SCIENCE ADVANCES 2023; 9:eadg4730. [PMID: 37418518 DOI: 10.1126/sciadv.adg4730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 06/05/2023] [Indexed: 07/09/2023]
Abstract
Bound states in the continuum (BICs) present a unique solution for eliminating radiation loss. So far, most reported BICs are observed in transmission spectra, with only a few exceptions being in reflection spectra. The correlation between reflection BICs (r-BICs) and transmission BICs (t-BICs) remains unclear. Here, we report the presence of both r-BICs and t-BICs in a three-mode cavity magnonics. We develop a generalized framework of non-Hermitian scattering Hamiltonians to explain the observed bidirectional r-BICs and unidirectional t-BICs. In addition, we find the emergence of an ideal isolation point in the complex frequency plane, where the isolation direction can be switched by fine frequency detuning, thanks to chiral symmetry protection. Our results demonstrate the potential of cavity magnonics and also extend the conventional BICs theory through the application of a more generalized effective Hamiltonians theory. This work offers an alternative idea for designing functional devices in general wave optics.
Collapse
Affiliation(s)
- Youcai Han
- State Key Laboratory of Surface Physics, Institute of Nanoelectronic Devices and Quantum Computing, Department of Physics, Fudan University, Shanghai 200433, China
| | - Changhao Meng
- State Key Laboratory of Surface Physics, Institute of Nanoelectronic Devices and Quantum Computing, Department of Physics, Fudan University, Shanghai 200433, China
| | - Hong Pan
- State Key Laboratory of Surface Physics, Institute of Nanoelectronic Devices and Quantum Computing, Department of Physics, Fudan University, Shanghai 200433, China
| | - Jie Qian
- State Key Laboratory of Surface Physics, Institute of Nanoelectronic Devices and Quantum Computing, Department of Physics, Fudan University, Shanghai 200433, China
| | - Zejin Rao
- State Key Laboratory of Surface Physics, Institute of Nanoelectronic Devices and Quantum Computing, Department of Physics, Fudan University, Shanghai 200433, China
| | - Liping Zhu
- State Key Laboratory of Surface Physics, Institute of Nanoelectronic Devices and Quantum Computing, Department of Physics, Fudan University, Shanghai 200433, China
| | - Yongsheng Gui
- Department of Physics and Astronomy, University of Manitoba, Winnipeg R3T 2N2, Canada
| | - Can-Ming Hu
- Department of Physics and Astronomy, University of Manitoba, Winnipeg R3T 2N2, Canada
| | - Zhenghua An
- State Key Laboratory of Surface Physics, Institute of Nanoelectronic Devices and Quantum Computing, Department of Physics, Fudan University, Shanghai 200433, China
- Shanghai Qi Zhi Institute, 41st Floor, AI Tower, No. 701 Yunjin Road, Xuhui District, Shanghai, 200232, China
- Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
- Yiwu Research Institute of Fudan University, Chengbei Road, Yiwu City, 322000 Zhejiang, China
| |
Collapse
|
21
|
Qu Y, Lei L, Yu Y, Zhang X, Xu P, Qian Z. Dual-band achromatic metalens-assisted grating couplers for wavelength demultiplexing. OPTICS EXPRESS 2023; 31:20787-20795. [PMID: 37381194 DOI: 10.1364/oe.495404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 05/31/2023] [Indexed: 06/30/2023]
Abstract
The design of grating couplers (GCs) that can (de)multiplex and couple arbitrarily defined spatial light into photonic devices is crucial for miniaturized integrated chips. However, traditional GCs have a limited optical bandwidth due to their wavelength's dependency on the coupling angle. In this paper, we propose a device that addresses this limitation by combining a dual-broadband achromatic metalens (ML) with two focusing GCs. By controlling the frequency dispersion, the waveguide-mode-based ML achieves excellent dual-broadband achromatic convergence and separates broadband spatial light into opposing directions at normal incidence. The focused and separated light field matches the grating diffractive mode field and is then coupled into two waveguides by the GCs. This ML-assisted GCs device exhibits a good broadband property with -3 dB bandwidths of 80 nm at 1.31 µm (CE ∼ -6 dB) and 85 nm at 1.51 µm (CE ∼ -5 dB), which almost covers the entire designed working bands, representing an improvement over traditional spatial light-GC coupling. This device can be integrated into optical transceivers and dual-band photodetectors to enhance the bandwidth of wavelength (de)multiplexing.
Collapse
|
22
|
Abstract
The topological properties of an object, associated with an integer called the topological invariant, are global features that cannot change continuously but only through abrupt variations, hence granting them intrinsic robustness. Engineered metamaterials (MMs) can be tailored to support highly nontrivial topological properties of their band structure, relative to their electronic, electromagnetic, acoustic and mechanical response, representing one of the major breakthroughs in physics over the past decade. Here, we review the foundations and the latest advances of topological photonic and phononic MMs, whose nontrivial wave interactions have become of great interest to a broad range of science disciplines, such as classical and quantum chemistry. We first introduce the basic concepts, including the notion of topological charge and geometric phase. We then discuss the topology of natural electronic materials, before reviewing their photonic/phononic topological MM analogues, including 2D topological MMs with and without time-reversal symmetry, Floquet topological insulators, 3D, higher-order, non-Hermitian and nonlinear topological MMs. We also discuss the topological aspects of scattering anomalies, chemical reactions and polaritons. This work aims at connecting the recent advances of topological concepts throughout a broad range of scientific areas and it highlights opportunities offered by topological MMs for the chemistry community and beyond.
Collapse
Affiliation(s)
- Xiang Ni
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
- School of Physics and Electronics, Central South University, Changsha, Hunan 410083, China
| | - Simon Yves
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
| | - Alex Krasnok
- Department of Electrical and Computer Engineering, Florida International University, Miami, Florida 33174, USA
| | - Andrea Alù
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
- Department of Electrical Engineering, City College, The City University of New York, 160 Convent Avenue, New York, New York 10031, United States
- Physics Program, The Graduate Center, The City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
| |
Collapse
|
23
|
Cai H, Li J, Mao L. Perfect linear polarization wave generator based on quasi-bound states in the continuum. OPTICS LETTERS 2023; 48:2559-2562. [PMID: 37186708 DOI: 10.1364/ol.487655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Quasi-bound states in the continuum (q-BICs) in optical metasurfaces have been found to carry special radiation polarization properties. Herein, we have studied the relationship between the radiation polarization state of a q-BIC and the polarization state of the output wave, and theoretically proposed a perfect linear polarization wave generator controlled by the q-BIC. The proposed q-BIC has an x-polarized radiation state, and the y co-polarized output wave is completely eliminated by introducing additional resonance at the q-BIC frequency. Finally, a perfect x-polarized transmission wave with very low background scattering is obtained, and the transmission polarization state is not limited by the incident polarization state. The device can be used to efficiently obtain narrowband linearly polarized waves from non-polarized waves, and can also be used for polarization-sensitive high-performance spatial filtering.
Collapse
|
24
|
Yulaev A, Westly DA, Aksyuk VA. Surface-Normal Free-Space Beam Projection via Slow-Light Standing-Wave Resonance Photonic Gratings. ACS PHOTONICS 2023; 10:945-952. [PMID: 37096211 PMCID: PMC10119973 DOI: 10.1021/acsphotonics.2c00422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Indexed: 05/03/2023]
Abstract
On-chip grating couplers directly connect photonic circuits to free-space light. The commonly used photonic gratings have been specialized for small areas, specific intensity profiles, and nonvertical beam projection. This falls short of the precise and flexible wavefront control over large beam areas needed to empower emerging integrated miniaturized optical systems that leverage volumetric light-matter interactions, including trapping, cooling, and interrogation of atoms, bio- and chemi- sensing, and complex free-space interconnect. The large coupler size challenges general inverse design techniques, and solutions obtained by them are often difficult to physically understand and generalize. Here, by posing the problem to a carefully constrained computational inverse-design algorithm capable of large area structures, we discover a qualitatively new class of grating couplers. The numerically found solutions can be understood as coupling an incident photonic slab mode to a spatially extended slow-light (near-zero refractive index) region, backed by a reflector. The structure forms a spectrally broad standing wave resonance at the target wavelength, radiating vertically into free space. A reflectionless adiabatic transition critically couples the incident photonic mode to the resonance, and the numerically optimized lower cladding provides 70% overall theoretical conversion efficiency. We have experimentally validated an efficient surface normal collimated emission of ≈90 μm full width at half-maximum Gaussian at the thermally tunable operating wavelength of ≈780 nm. The variable-mesh-deformation inverse design approach scales to extra large photonic devices, while directly implementing the fabrication constraints. The deliberate choice of smooth parametrization resulted in a novel type of solution, which is both efficient and physically comprehensible.
Collapse
Affiliation(s)
- Alexander Yulaev
- Physical
Measurement Laboratory, National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
- Department
of Chemistry and Biochemistry, University
of Maryland, College Park, Maryland 20742, United States
| | - Daron A. Westly
- Physical
Measurement Laboratory, National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Vladimir A. Aksyuk
- Physical
Measurement Laboratory, National Institute
of Standards and Technology, Gaithersburg, Maryland 20899, United States
- Ph: (301) 975-2867.
| |
Collapse
|
25
|
Li H, Zhou H, Wei G, Xu H, Qin M, Liu J, Wu F. Photonic spin-selective perfect absorptance on planar metasurfaces driven by chiral quasi-bound states in the continuum. NANOSCALE 2023; 15:6636-6644. [PMID: 36877541 DOI: 10.1039/d3nr00055a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Optical metasurfaces with high-quality-factor resonances and selective chirality simultaneously are desired for nanophotonics. Here, an all-dielectric planar chiral metasurface is theoretically proposed and numerically proved to support the astonishing symmetry-protected bound state in the continuum (BIC), due to the preserved π rotational symmetry around the z axis and up-down mirror symmetry simultaneously. Importantly, such BIC is a vortex polarization singularity enclosed by elliptical eigenstate polarizations with non-vanishing helicity, owing to the broken in-plane mirror symmetry. Under the oblique incidence, companied by the BIC transforming into a quasi-BIC (Q-BIC), the strong extrinsic chirality manifests. Assisted by the single-port critical coupling, the planar metasurface can selectively and near-perfectly absorb one circularly polarized light but non-resonantly reflect its counterparts. The circular dichroism (CD) approaching 0.812 is achieved. Intriguingly, the sign of CD (namely, the handedness of the chiral metasurface) can be flexibly manipulated only via varying the azimuthal angle of incident light, due to the periodic helicity sign flip in eigen polarizations around the BIC. Numerical results are consistent with the coupled-mode theory and multipole decomposition method. The spin-selective metasurface absorber empowered by the physics of chiral Q-BICs undoubtedly may promise various applications such as optical filters, polarization detectors, and chiral imaging.
Collapse
Affiliation(s)
- Hongju Li
- School of Physics, Hefei University of Technology, Hefei, Anhui 230009, China.
| | - Hongmiao Zhou
- School of Physics, Hefei University of Technology, Hefei, Anhui 230009, China.
| | - Gangao Wei
- School of Physics, Hefei University of Technology, Hefei, Anhui 230009, China.
| | - Hangsheng Xu
- School of Physics, Hefei University of Technology, Hefei, Anhui 230009, China.
| | - Meng Qin
- School of Physics, Hefei University of Technology, Hefei, Anhui 230009, China.
| | - Jianqiang Liu
- School of Science, Jiujiang University, Jiujiang 332005, China
| | - Feng Wu
- School of Optoelectronic Engineering, Guangdong Polytechnic Normal University, Guangzhou 510665, China
| |
Collapse
|
26
|
Qin H, Su Z, Liu M, Zeng Y, Tang MC, Li M, Shi Y, Huang W, Qiu CW, Song Q. Arbitrarily polarized bound states in the continuum with twisted photonic crystal slabs. LIGHT, SCIENCE & APPLICATIONS 2023; 12:66. [PMID: 36878927 PMCID: PMC9988870 DOI: 10.1038/s41377-023-01090-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 12/30/2022] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
Arbitrary polarized vortex beam induced by polarization singularity offers a new platform for both classical optics and quantum entanglement applications. Bound states in the continuum (BICs) have been demonstrated to be associated with topological charge and vortex polarization singularities in momentum space. For conventional symmetric photonic crystal slabs (PhCSs), BIC is enclosed by linearly polarized far fields with winding angle of 2π, which is unfavorable for high-capacity and multi-functionality integration-optics applications. Here, we show that by breaking σz-symmetry of the PhCS, asymmetry in upward and downward directions and arbitrarily polarized BIC can be realized with a bilayer-twisted PhCS. It exhibits elliptical polarization states with constant ellipticity angle at every point in momentum space within the vicinity of BIC. The topological nature of BIC reflects on the orientation angle of polarization state, with a topological charge of 1 for any value of ellipticity angle. Full coverage of Poincaré sphere (i.e., [Formula: see text] and [Formula: see text]) and higher-order Poincaré sphere can be realized by tailoring the twist angles. Our findings may open up new avenues for applications in structured light, quantum optics, and twistronics for photons.
Collapse
Affiliation(s)
- Haoye Qin
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Zengping Su
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Mengqi Liu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Yixuan Zeng
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Man-Chung Tang
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Mengyao Li
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Yuzhi Shi
- Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Wei Huang
- Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences (CAS), Suzhou, 215123, China
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583, Singapore.
| | - Qinghua Song
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China.
| |
Collapse
|
27
|
Chong MZ, He Y, Zhao J, Zhang YY, Zhang ZK, Zhang CQ, Du CH, Zang X, Liu PK. Spin-decoupled excitation and wavefront shaping of structured surface waves via on-chip terahertz metasurfaces. NANOSCALE 2023; 15:4515-4522. [PMID: 36757161 DOI: 10.1039/d2nr06983k] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Surface waves (SWs) are of great importance in terahertz (THz) photonics applications due to their subwavelength properties. Hence, it is crucial to develop surface wavefront shaping techniques, which is urgent in modern information technologies. In this paper, a new scheme is proposed to realize SW excitation and spin-decoupled wavefront shaping with an ultracompact planar meta-device working in the THz range. The meta-device is composed of two parts: meta-atoms (in the center) and plasmonic metals (on the left and right sides). By carefully setting the geometry size and rotation angle of each meta-atom, the encoded spin-decoupled phase distributions for both left circularly polarized (LCP) and right circularly polarized (RCP) incident THz waves are determined. In this way, circularly polarized (CP) incident THz waves can be converted to SWs propagating along plasmonic metals with unique wavefront profiles, i.e., Bessel and focusing profiles. Full-wave simulations and THz near-field scanning experiments were performed to verify the functionalities of the meta-device, both of which are in great agreement with theoretical predictions. Our findings may provide more solutions to design THz integrated photonic devices and systems.
Collapse
Affiliation(s)
- Ming-Zhe Chong
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, Peking University, Beijing, 100871, China.
| | - Yidan He
- Key Laboratory for the Physics and Chemistry of Nanodevices, School of Electronics, Peking University, Beijing, 100871, China
| | - Jin Zhao
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, Peking University, Beijing, 100871, China.
| | - Yue-Yi Zhang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, Peking University, Beijing, 100871, China.
| | - Zong-Kun Zhang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, Peking University, Beijing, 100871, China.
| | - Chong-Qi Zhang
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, Peking University, Beijing, 100871, China.
| | - Chao-Hai Du
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, Peking University, Beijing, 100871, China.
| | - Xiaofei Zang
- Terahertz Technology Innovation Research Institute, and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 JunGong Road, Shanghai, 200093, China.
| | - Pu-Kun Liu
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, Peking University, Beijing, 100871, China.
| |
Collapse
|
28
|
Yin X, Inoue T, Peng C, Noda S. Topological Unidirectional Guided Resonances Emerged from Interband Coupling. PHYSICAL REVIEW LETTERS 2023; 130:056401. [PMID: 36800480 DOI: 10.1103/physrevlett.130.056401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 12/05/2022] [Indexed: 06/18/2023]
Abstract
Unidirectional guided resonances (UGRs) are optical modes in photonic crystal slabs that radiate toward one side without the need for mirrors on the other. In this Letter, we report a mechanism to realize UGRs by tuning the interband coupling effect originating from up-down symmetry breaking. We theoretically find that UGRs that reside along high-symmetric lines correspond to phase singularities of far-field radiation, depicted by phase winding numbers as a type of topological indices. We investigate the phase dislocation lines in three-dimensional parameter space and elaborate on the interplay between UGRs and non-Hermitian degeneracies accordingly. Our findings reveal the topological nature of UGRs about their generation, evolution, and annihilation in general parameter spaces, thus paving the way to new possibilities of light manipulation.
Collapse
Affiliation(s)
- Xuefan Yin
- Department of Electronic Science and Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Takuya Inoue
- Department of Electronic Science and Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Chao Peng
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing, 100871, China
- Peng Cheng Laboratory, Shenzhen 518055, China
| | - Susumu Noda
- Department of Electronic Science and Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| |
Collapse
|
29
|
Observation of intrinsic chiral bound states in the continuum. Nature 2023; 613:474-478. [PMID: 36653568 DOI: 10.1038/s41586-022-05467-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 10/20/2022] [Indexed: 01/20/2023]
Abstract
Photons with spin angular momentum possess intrinsic chirality, which underpins many phenomena including nonlinear optics1, quantum optics2, topological photonics3 and chiroptics4. Intrinsic chirality is weak in natural materials, and recent theoretical proposals5-7 aimed to enlarge circular dichroism by resonant metasurfaces supporting bound states in the continuum that enhance substantially chiral light-matter interactions. Those insightful works resort to three-dimensional sophisticated geometries, which are too challenging to be realized for optical frequencies8. Therefore, most of the experimental attempts9-11 showing strong circular dichroism rely on false/extrinsic chirality by using either oblique incidence9,10 or structural anisotropy11. Here we report on the experimental realization of true/intrinsic chiral response with resonant metasurfaces in which the engineered slant geometry breaks both in-plane and out-of-plane symmetries. Our result marks, to our knowledge, the first observation of intrinsic chiral bound states in the continuum with near-unity circular dichroism of 0.93 and a high quality factor exceeding 2,663 for visible frequencies. Our chiral metasurfaces may lead to a plethora of applications in chiral light sources and detectors, chiral sensing, valleytronics and asymmetric photocatalysis.
Collapse
|
30
|
Xu Q, Peng Y, Yan B, Shi A, Peng P, Xie J, Liu J. Multiband topological states in the Penrose-triangle photonic crystals. OPTICS LETTERS 2023; 48:101-104. [PMID: 36563382 DOI: 10.1364/ol.477077] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 11/16/2022] [Indexed: 06/17/2023]
Abstract
The topological edge state (TES) and topological corner state (TCS) in photonic crystals (PCs) provide effective ways to manipulate the propagation of light. To improve the performance and integration of topological photonic devices, the realization of multiband topological states by PCs combined with quasi-periodic structure needs to be urgently explored. In this Letter, a Penrose-triangle (P-T) PC, which arranges the basic structural unit of a 12-fold Penrose-type photonic quasi-crystal (PQC) in a triangular lattice, is proposed. The TES and TCS at low- and high-frequency bands can be generated in the same structure, accompanied by the realization of three groups of TCSs. This will provide a new structure for the generation of TESs and TCSs in PCs, and will provide a new way to improve the performance and integration of topological photonic devices.
Collapse
|
31
|
Wang J, Shi L, Zi J. Spin Hall Effect of Light via Momentum-Space Topological Vortices around Bound States in the Continuum. PHYSICAL REVIEW LETTERS 2022; 129:236101. [PMID: 36563232 DOI: 10.1103/physrevlett.129.236101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
Optical bound states in the continuum (BICs) are exotic topological defects in photonic crystal slabs, carrying polarization topological vortices in momentum space. The topological vortex configurations not only topologically protect the infinite radiation lifetime of BICs, but also intrinsically contain many unexploited degrees of freedom for light manipulation originating from BICs. Here, we theoretically propose and experimentally demonstrate the spin Hall effect of light in photonic crystal slabs via momentum-space topological vortices around BICs. The strong spin-orbit interactions of light are induced by using the topological vortices around BICs, introducing both wave-vector-dependent Pancharatnam-Berry phase gradients and cross-polarized resonant phase gradients to the spinning light beam, which lead to spin-dependent in-plane-oblique lateral light beam shifts. Our work reveals intriguing spin-related topological effects around BICs, opening an avenue toward applications of BICs in integrated spin-optical devices and information processing.
Collapse
Affiliation(s)
- Jiajun Wang
- State Key Laboratory of Surface Physics, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education) and Department of Physics, Fudan University, Shanghai 200433, China
| | - Lei Shi
- State Key Laboratory of Surface Physics, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education) and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200438, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jian Zi
- State Key Laboratory of Surface Physics, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education) and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200438, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| |
Collapse
|
32
|
Nano-electromechanical spatial light modulator enabled by asymmetric resonant dielectric metasurfaces. Nat Commun 2022; 13:5811. [PMID: 36192401 PMCID: PMC9530114 DOI: 10.1038/s41467-022-33449-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 09/20/2022] [Indexed: 11/17/2022] Open
Abstract
Spatial light modulators (SLMs) play essential roles in various free-space optical technologies, offering spatio-temporal control of amplitude, phase, or polarization of light. Beyond conventional SLMs based on liquid crystals or microelectromechanical systems, active metasurfaces are considered as promising SLM platforms because they could simultaneously provide high-speed and small pixel size. However, the active metasurfaces reported so far have achieved either limited phase modulation or low efficiency. Here, we propose nano-electromechanically tunable asymmetric dielectric metasurfaces as a platform for reflective SLMs. Exploiting the strong asymmetric radiation of perturbed high-order Mie resonances, the metasurfaces experimentally achieve a phase-shift close to 290∘, over 50% reflectivity, and a wavelength-scale pixel size. Electrical control of diffraction patterns is also achieved by displacing the Mie resonators using nano-electro-mechanical forces. This work paves the ways for future exploration of the asymmetric metasurfaces and for their application to the next-generation SLMs. This work experimentally demonstrates nano-electromechanically tunable asymmetric dielectric metasurfaces. The metasurfaces enable large phase tuning, high reflection, a wavelength-scale pixel size, and electrical control of diffraction patterns.
Collapse
|
33
|
Sun H, Yuan S, Feng C, Zhang J, Zeng C, Xia J. Enhanced bound states in the continuum in a DBR-assisted photonic crystal slab. APPLIED OPTICS 2022; 61:8527-8532. [PMID: 36256170 DOI: 10.1364/ao.471587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
Bound states in the continuum (BICs) are perfectly confined resonances within the radiation continuum. The novel characteristics of single BICs have been studied in great detail in various wave systems, including electromagnetic waves, acoustic waves, water waves, and elastic waves in solids. In practice, the performance of BICs is limited by the finite size of the structure, while the combination of multiple BICs can further improve the localization of resonances. In this study, we experimentally demonstrate the combination of Fabry-Perot and symmetry-protected BICs at near infrared wavelengths by employing a compound photonic crystal system composed of a photonic crystal slab and a distributed Bragg reflector, resulting in an enhanced high quality factor.
Collapse
|
34
|
Abdelraouf OAM, Wang Z, Liu H, Dong Z, Wang Q, Ye M, Wang XR, Wang QJ, Liu H. Recent Advances in Tunable Metasurfaces: Materials, Design, and Applications. ACS NANO 2022; 16:13339-13369. [PMID: 35976219 DOI: 10.1021/acsnano.2c04628] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Metasurfaces, a two-dimensional (2D) form of metamaterials constituted by planar meta-atoms, exhibit exotic abilities to tailor electromagnetic (EM) waves freely. Over the past decade, tremendous efforts have been made to develop various active materials and incorporate them into functional devices for practical applications, pushing the research of tunable metasurfaces to the forefront of nanophotonics. Those active materials include phase change materials (PCMs), semiconductors, transparent conducting oxides (TCOs), ferroelectrics, liquid crystals (LCs), atomically thin material, etc., and enable intriguing performances such as fast switching speed, large modulation depth, ultracompactness, and significant contrast of optical properties under external stimuli. Integration of such materials offers substantial tunability to the conventional passive nanophotonic platforms. Tunable metasurfaces with multifunctionalities triggered by various external stimuli bring in rich degrees of freedom in terms of material choices and device designs to dynamically manipulate and control EM waves on demand. This field has recently flourished with the burgeoning development of physics and design methodologies, particularly those assisted by the emerging machine learning (ML) algorithms. This review outlines recent advances in tunable metasurfaces in terms of the active materials and tuning mechanisms, design methodologies, and practical applications. We conclude this review paper by providing future perspectives in this vibrant and fast-growing research field.
Collapse
Affiliation(s)
- Omar A M Abdelraouf
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Ziyu Wang
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Hailong Liu
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Zhaogang Dong
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Qian Wang
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Ming Ye
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Xiao Renshaw Wang
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Qi Jie Wang
- School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Hong Liu
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| |
Collapse
|
35
|
Abstract
Ultracompact sources of circularly polarized light are important for classical and quantum optical information processing. Conventional approaches for generating chiral emission are restricted to excitation power ranges and fail to provide high-quality radiation with perfect polarization conversion. We used the physics of chiral quasi-bound states in the continuum to demonstrate the efficient and controllable emission of circularly polarized light from resonant metasurfaces. Exploiting intrinsic chirality and giant field enhancement, we revealed how to simultaneously modify and control spectra, radiation patterns, and spin angular momentum of photoluminescence and lasing without any spin injection. The superior characteristics of chiral emission and lasing promise multiple applications in nanophotonics and quantum optics.
Collapse
Affiliation(s)
- Xudong Zhang
- Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Harbin Institute of Technology, Shenzhen 518055, P. R. China
| | - Yilin Liu
- Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Harbin Institute of Technology, Shenzhen 518055, P. R. China
| | - Jiecai Han
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150080, P. R. China
| | - Yuri Kivshar
- Nonlinear Physics Center, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - Qinghai Song
- Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Harbin Institute of Technology, Shenzhen 518055, P. R. China.,Pengcheng Laboratory, Shenzhen 518055, P. R. China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, P. R. China
| |
Collapse
|
36
|
Abstract
Topological insulators (TIs) have attracted significant attention in photonics and acoustics due to their unique physical properties and promising applications. Electronics has recently emerged as an exciting arena to study various topological phenomena because of its advantages in building complex topological structures. Here, we explore TIs on an integrated circuit (IC) platform with a standard complementary metal-oxide-semiconductor technology. Based on the Su–Schrieffer–Heeger model, we design a fully integrated topological circuit chain using multiple capacitively-coupled inductor–capacitor resonators. We perform comprehensive post-layout simulations on its physical layout to observe and evaluate the salient topological features. Our results demonstrate the existence of the topological edge state and the remarkable robustness of the edge state against various defects. Our work shows the feasibility and promise of studying TIs with IC technology, paving the way for future explorations of large-scale topological electronics on the scalable IC platform.
Collapse
|
37
|
Kang M, Mao L, Zhang S, Xiao M, Xu H, Chan CT. Merging bound states in the continuum by harnessing higher-order topological charges. LIGHT, SCIENCE & APPLICATIONS 2022; 11:228. [PMID: 35853861 PMCID: PMC9296527 DOI: 10.1038/s41377-022-00923-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
Bound states in the continuum (BICs) can confine light with a theoretically infinite Q factor. However, in practical on-chip resonators, scattering loss caused by inevitable fabrication imperfection leads to finite Q factors due to the coupling of BICs with nearby radiative states. Merging multiple BICs can improve the robustness of BICs against fabrication imperfection by improving the Q factors of nearby states over a broad wavevector range. To date, the studies of merging BICs have been limited to fundamental BICs with topological charges ±1. Here we show the unique advantages of higher-order BICs (those with higher-order topological charges) in constructing merging BICs. Merging multiple BICs with a higher-order BIC can further improve the Q factors compared with those involving only fundamental BICs. In addition, higher-order BICs offer great flexibility in realizing steerable off-Γ merging BICs. A higher-order BIC at Γ can split into a few off-Γ fundamental BICs by reducing the system symmetry. The split BICs can then be tuned to merge with another BIC, e.g., an accidental BIC, at an off-Γ point. When the in-plane mirror symmetry is further broken, merging BICs become steerable in the reciprocal space. Merging BICs provide a paradigm to achieve robust ultrahigh-Q resonances, which are important in enhancing nonlinear and quantum effects and improving the performance of optoelectronic devices.
Collapse
Affiliation(s)
- Meng Kang
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
- Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Li Mao
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
- Wuhan Institute of Quantum Technology, Wuhan, 430206, China
| | - Shunping Zhang
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
- Wuhan Institute of Quantum Technology, Wuhan, 430206, China
| | - Meng Xiao
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China.
- Wuhan Institute of Quantum Technology, Wuhan, 430206, China.
| | - Hongxing Xu
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
- Wuhan Institute of Quantum Technology, Wuhan, 430206, China
- School of Microelectronics, Wuhan University, Wuhan, 430072, China
| | - Che Ting Chan
- Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China.
| |
Collapse
|
38
|
Mantsevich VN, Smirnov DS. Current-induced hole spin polarization in a quantum dot via a chiral quasi bound state. NANOSCALE HORIZONS 2022; 7:752-758. [PMID: 35593642 DOI: 10.1039/d1nh00685a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We put forward a mechanism for the current-induced spin polarization in semiconductor heterostructures, which is based on the complex structure of the valence band. It takes place for a light hole in a quantum dot side-coupled to a quantum wire with heavy holes. In stark contrast with the traditional mechanisms based on the linear in momentum spin-orbit coupling, an exponentially small bias applied to this structure is enough to create the 100% spin polarization in the quantum dot. Microscopically, this effect is related to the formation of the chiral quasi bound states and the spin-dependent tunneling of holes from the quantum wire to the quantum dot. This new concept is equally valid for the GaAs-, Si- and Ge-based nanostructures.
Collapse
Affiliation(s)
- V N Mantsevich
- Chair of Semiconductors and Cryoelectronics & Quantum Technology Center, Physics department, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - D S Smirnov
- Ioffe Institute, 194021 St. Petersburg, Russia.
| |
Collapse
|
39
|
Huang L, Zhang W, Zhang X. Moiré Quasibound States in the Continuum. PHYSICAL REVIEW LETTERS 2022; 128:253901. [PMID: 35802444 DOI: 10.1103/physrevlett.128.253901] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
The novel physics of twisted bilayer graphene has motivated extensive studies of magic-angle flat bands hosted by moiré structures in electronic, photonic, and acoustic systems. On the other hand, bound states in the continuum (BICs) have also attracted great attention in recent years because of their potential applications in the field of designing superior optical devices. Here, we combine these two independent concepts to construct a new optical state in a twisted bilayer photonic crystal slab, which is called as moiré quasi-BIC, and numerically demonstrate that such an exotic optical state possesses dual characteristics of moiré flat bands and quasi-BICs. To illustrate the mechanism for the formation of moiré flat bands, we develop an effective model at the center of the Brillouin zone and show that moiré flat bands could be fulfilled by balancing the interlayer coupling strength and the twist angle around the band edge above the light line. Moreover, by decreasing the twist angle of moiré photonic crystal slabs with flat bands, it is shown that the moiré flat-band mode at the Brillouin center gradually approaches a perfect BIC, where the total radiation loss from all diffraction channels is significantly suppressed. To clarify the advantage of moiré quasi-BICs, enhanced second-harmonic generation (SHG) is numerically proven with a wide-angle optical source. The efficiency of SHG assisted by designed moiré quasi-BICs can be greatly improved compared with that based on dispersive quasi-BICs with similar quality factors.
Collapse
Affiliation(s)
- Lei Huang
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081, Beijing, China
| | - Weixuan Zhang
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081, Beijing, China
| | - Xiangdong Zhang
- Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements of Ministry of Education, Beijing Key Laboratory of Nanophotonics & Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, 100081, Beijing, China
| |
Collapse
|
40
|
Chen Y, Liu Z, Li Y, Hu Z, Wu J, Wang J. Adjustable converter of bound state in the continuum basing on metal-graphene hybrid metasurfaces. OPTICS EXPRESS 2022; 30:23828-23839. [PMID: 36225056 DOI: 10.1364/oe.462221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/03/2022] [Indexed: 06/16/2023]
Abstract
The bound state in the continuum (BIC) is widely applied to metamaterial study in order to obtain robust resonance and high quality (Q) factor. In this paper, we propose a metallic metasurface structure that can support double types of BICs, and acquire quasi-BIC state by restructuring each type with a specific approach. Electric field distribution is investigated to explore the physic mechanism behind the evolution of BICs. Moreover, we substitute structured graphene with corresponding metal counterparts. The promoted design is able to switch freely between BIC and quasi-BIC state even after the fabrication, as the graphene would convert from semiconductor-like to metal-like when increasing the Fermi level. Further exploration on electric field distribution demonstrates the metallicity difference between graphene and gold, which leads to the exotic phenomenon emerge on the proposed metal-graphene structure. Finally, the proposed metal-graphene structure is applied to a digital coding display through Fermi level regulating. Therefore, our work provides deep insights to the BIC metasurface investigation, and introduces a desirable improvement for current BIC metasurface design to achieve the free conversion between BIC and quasi-BIC states.
Collapse
|
41
|
Feng Y, Zhang Z, Qin F, Lan Z, Sha WEI, Xu Y. Bound valley edge states in the continuum. OPTICS LETTERS 2022; 47:3107-3110. [PMID: 35709062 DOI: 10.1364/ol.463458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
Topological valley photonics provides a unique way to manipulate the flow of light. In general, valley edge states that exhibit unidirectional propagation and are immune to defects and disorders could be realized at the interface between two valley photonic crystals with opposite valley Chern numbers. Herein, by merging the physics of valley edge states and bound states in the continuum, we propose and numerically demonstrate a novel, to the best of our knowledge, concept of edge states termed bound valley edge states in the continuum, which enjoys the topological features of valley edge states, such as, unidirectional propagation and immunity to disorders, but are formed at the interface between air and a single valley photonic crystal. Our results not only provide an effective way to reduce the size of valley photonic structures but also facilitate new applications where the proposed concept of bound valley edge states in the continuum could be exploited for optical sensing and unidirectional waveguiding.
Collapse
|
42
|
Zhang Z, Wang F, Wang H, Hu Y, Yin X, Hu W, Peng C. All-pass phase shifting enabled by symmetric topological unidirectional guided resonances. OPTICS LETTERS 2022; 47:2875-2878. [PMID: 35648953 DOI: 10.1364/ol.460435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/15/2022] [Indexed: 06/15/2023]
Abstract
All-pass phase shifting (APS), which involves a wave propagating at a constant, unitary amplitude but with pure phase variation, is extremely desired in many optoelectronic applications. In this work, we propose a method of realizing APS by out-of-plane excitation of a topologically enabled unidirectional guided resonance (UGR), which resides in a photonic crystal slab with P or C2z symmetries. Briefly, the symmetries and unidirectional features reduce the number of ports to one that simultaneously adds or drops energy. As a result, the phase independently shifts by varying the frequency but the amplitude remains as unitary under plane wave excitation. Theory and simulations confirm our findings. A paradox that the background contribution deviates from Fabry-Perot resonance is clarified from a multi-resonances picture.
Collapse
|
43
|
Zhao C, Dong S, Zhang Q, Zeng Y, Hu G, Zhang Y. Magnetic modulation of topological polarization singularities in momentum space. OPTICS LETTERS 2022; 47:2754-2757. [PMID: 35648922 DOI: 10.1364/ol.458285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 04/29/2022] [Indexed: 06/15/2023]
Abstract
The polarization singularities in momentum space, rather than in real space, are capturing interest for active singular optics with exotic light scattering and various topological phenomena, which have potential applications in vortex nano-lasers, valley exciton emission, and others. Here, we propose to magnetically control the polarization singularities in momentum space in the photonic crystal slabs with inversion spatial symmetry (P symmetry). A pair of C points (circular polarization points) with the same topological charge is spawned from a V point (polarization vortex center), and they can be dynamically shifted in momentum space with the variation of the magnetic field. Moreover, the coupling between transverse electric (TE) and transverse magnetic (TM) modes induced by the magnetic field gives rise to a hybrid mode, which can close certain leaky channels to achieve an accidental V point. Such active manipulation of polarization singularities with magnetic field is promised for various applications in light-matter interactions and reveals novel phenomena and physics in singular optics and topological photonics.
Collapse
|
44
|
Yang G, Dev SU, Allen MS, Allen JW, Harutyunyan H. Optical Bound States in the Continuum Enabled by Magnetic Resonances Coupled to a Mirror. NANO LETTERS 2022; 22:2001-2008. [PMID: 35175777 DOI: 10.1021/acs.nanolett.1c04764] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Dielectric metasurfaces made of high refractive index and low optical loss materials have emerged as promising platforms to achieve high-quality factor modes enabling strong light-matter interaction. Bound states in the continuum have shown potential to demonstrate narrow spectral resonances but often require asymmetric geometry and typically feature strong polarization dependence, complicating fabrication and limiting practical applications. We introduce a novel approach for designing high-quality bound states in the continuum using magnetic dipole resonances coupled to a mirror. The resulting metasurface has simple geometric parameters requiring no broken symmetry. To demonstrate the unique features of our photonic platform we show a record-breaking third harmonic generation efficiency from the metasurface benefiting from the strongly enhanced electric field at high-quality resonances. Our approach mitigates the shortcomings of previous platforms with simple geometry enabling facile and large-area fabrication of metasurfaces paving the way for applications in optical sensing, detection, quantum photonics, and nonlinear devices.
Collapse
Affiliation(s)
- Guoce Yang
- Department of Physics, Emory University, Atlanta, Georgia 30322, United States
| | - Sukrith U Dev
- Air Force Research Laboratory, Munitions Directorate, Eglin AFB, Florida 32542, United States
| | - Monica S Allen
- Air Force Research Laboratory, Munitions Directorate, Eglin AFB, Florida 32542, United States
| | - Jeffery W Allen
- Air Force Research Laboratory, Munitions Directorate, Eglin AFB, Florida 32542, United States
| | - Hayk Harutyunyan
- Department of Physics, Emory University, Atlanta, Georgia 30322, United States
| |
Collapse
|
45
|
Huang L, Krasnok A, Alú A, Yu Y, Neshev D, Miroshnichenko AE. Enhanced light-matter interaction in two-dimensional transition metal dichalcogenides. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:046401. [PMID: 34939940 DOI: 10.1088/1361-6633/ac45f9] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 12/16/2021] [Indexed: 05/27/2023]
Abstract
Two-dimensional (2D) transition metal dichalcogenide (TMDC) materials, such as MoS2, WS2, MoSe2, and WSe2, have received extensive attention in the past decade due to their extraordinary electronic, optical and thermal properties. They evolve from indirect bandgap semiconductors to direct bandgap semiconductors while their layer number is reduced from a few layers to a monolayer limit. Consequently, there is strong photoluminescence in a monolayer (1L) TMDC due to the large quantum yield. Moreover, such monolayer semiconductors have two other exciting properties: large binding energy of excitons and valley polarization. These properties make them become ideal materials for various electronic, photonic and optoelectronic devices. However, their performance is limited by the relatively weak light-matter interactions due to their atomically thin form factor. Resonant nanophotonic structures provide a viable way to address this issue and enhance light-matter interactions in 2D TMDCs. Here, we provide an overview of this research area, showcasing relevant applications, including exotic light emission, absorption and scattering features. We start by overviewing the concept of excitons in 1L-TMDC and the fundamental theory of cavity-enhanced emission, followed by a discussion on the recent progress of enhanced light emission, strong coupling and valleytronics. The atomically thin nature of 1L-TMDC enables a broad range of ways to tune its electric and optical properties. Thus, we continue by reviewing advances in TMDC-based tunable photonic devices. Next, we survey the recent progress in enhanced light absorption over narrow and broad bandwidths using 1L or few-layer TMDCs, and their applications for photovoltaics and photodetectors. We also review recent efforts of engineering light scattering, e.g., inducing Fano resonances, wavefront engineering in 1L or few-layer TMDCs by either integrating resonant structures, such as plasmonic/Mie resonant metasurfaces, or directly patterning monolayer/few layers TMDCs. We then overview the intriguing physical properties of different van der Waals heterostructures, and their applications in optoelectronic and photonic devices. Finally, we draw our opinion on potential opportunities and challenges in this rapidly developing field of research.
Collapse
Affiliation(s)
- Lujun Huang
- School of Engineering and Information Technology, University of New South Wales, Canberra, ACT, 2600, Australia
| | - Alex Krasnok
- Department of Electrical and Computer Engineering, Florida International University, Miami, FL 33174, United States of America
| | - Andrea Alú
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY 10031, United States of America
- Physics Program, Graduate Center, City University of New York, New York, NY 10016, United States of America
| | - Yiling Yu
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Dragomir Neshev
- ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS), Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - Andrey E Miroshnichenko
- School of Engineering and Information Technology, University of New South Wales, Canberra, ACT, 2600, Australia
| |
Collapse
|
46
|
Hu P, Xie C, Song Q, Chen A, Xiang H, Han D, Zi J. Bound states in the continuum based on the total internal reflection of Bloch waves. Natl Sci Rev 2022; 10:nwac043. [PMID: 36789104 PMCID: PMC9910412 DOI: 10.1093/nsr/nwac043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/08/2021] [Accepted: 02/15/2022] [Indexed: 11/14/2022] Open
Abstract
A photonic-crystal slab can support bound states in the continuum (BICs) that have infinite lifetimes but are embedded into the continuous spectrum of optical modes in free space. The formation of BICs requires a total internal reflection (TIR) condition at both interfaces between the slab and the free space. Here, we show that the TIR of Bloch waves can be directly obtained based on the generalized Fresnel equations proposed. If each of these Bloch waves picks up a phase with integer multiples of 2π for traveling a round trip, light can be perfectly guided in the slab, namely forming a BIC. A BIC solver with low computational complexity and fast convergence speed is developed, which can also work efficiently at high frequencies beyond the diffraction limit where multiple radiation channels exist. Two examples of multi-channel BICs are shown and their topological nature in momentum space is also revealed. Both can be attributed to the coincidence of the topological charges of far-field radiations from different radiation channels. The concept of the generalized TIR and the TIR-based BIC solver developed offer highly effective approaches for explorations of BICs that could have many potential applications in guided-wave optics and enhanced light-matter interactions.
Collapse
Affiliation(s)
| | | | - Qianju Song
- College of Physics, Chongqing University, Chongqing 401331, China
| | - Ang Chen
- State Key Laboratory of Surface Physics, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education) and Department of Physics, Fudan University, Shanghai 200433, China
| | - Hong Xiang
- College of Physics, Chongqing University, Chongqing 401331, China,Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing 401331, China
| | | | - Jian Zi
- Corresponding author. E-mail:
| |
Collapse
|
47
|
Chen Z, Yin X, Jin J, Zheng Z, Zhang Z, Wang F, He L, Zhen B, Peng C. Observation of miniaturized bound states in the continuum with ultra-high quality factors. Sci Bull (Beijing) 2022; 67:359-366. [DOI: 10.1016/j.scib.2021.10.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 11/24/2022]
|
48
|
Dong Z, Mahfoud Z, Paniagua-Domínguez R, Wang H, Fernández-Domínguez AI, Gorelik S, Ha ST, Tjiptoharsono F, Kuznetsov AI, Bosman M, Yang JKW. Nanoscale mapping of optically inaccessible bound-states-in-the-continuum. LIGHT, SCIENCE & APPLICATIONS 2022; 11:20. [PMID: 35058424 PMCID: PMC8776833 DOI: 10.1038/s41377-021-00707-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 12/01/2021] [Accepted: 12/30/2021] [Indexed: 06/02/2023]
Abstract
Bound-states-in-the-continuum (BIC) is an emerging concept in nanophotonics with potential impact in applications, such as hyperspectral imaging, mirror-less lasing, and nonlinear harmonic generation. As true BIC modes are non-radiative, they cannot be excited by using propagating light to investigate their optical characteristics. In this paper, for the 1st time, we map out the strong near-field localization of the true BIC resonance on arrays of silicon nanoantennas, via electron energy loss spectroscopy with a sub-1-nm electron beam. By systematically breaking the designed antenna symmetry, emissive quasi-BIC resonances become visible. This gives a unique experimental tool to determine the coherent interaction length, which we show to require at least six neighboring antenna elements. More importantly, we demonstrate that quasi-BIC resonances are able to enhance localized light emission via the Purcell effect by at least 60 times, as compared to unpatterned silicon. This work is expected to enable practical applications of designed, ultra-compact BIC antennas such as for the controlled, localized excitation of quantum emitters.
Collapse
Affiliation(s)
- Zhaogang Dong
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03 Innovis, 138634, Singapore, Singapore.
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore, Singapore.
| | - Zackaria Mahfoud
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03 Innovis, 138634, Singapore, Singapore
| | - Ramón Paniagua-Domínguez
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03 Innovis, 138634, Singapore, Singapore
| | - Hongtao Wang
- Singapore University of Technology and Design, 8 Somapah Road, 487372, Singapore, Singapore
| | - Antonio I Fernández-Domínguez
- Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Sergey Gorelik
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03 Innovis, 138634, Singapore, Singapore
- Singapore Institute of Food and Biotechnology Innovation, A*STAR (Agency for Science, Technology and Research), 31 Biopolis Way, #01-02 Nanos, 138669, Singapore, Singapore
| | - Son Tung Ha
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03 Innovis, 138634, Singapore, Singapore
| | - Febiana Tjiptoharsono
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03 Innovis, 138634, Singapore, Singapore
| | - Arseniy I Kuznetsov
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03 Innovis, 138634, Singapore, Singapore
| | - Michel Bosman
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03 Innovis, 138634, Singapore, Singapore.
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore, Singapore.
| | - Joel K W Yang
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03 Innovis, 138634, Singapore, Singapore.
- Singapore University of Technology and Design, 8 Somapah Road, 487372, Singapore, Singapore.
| |
Collapse
|
49
|
Zhou C, Pu T, Huang J, Fan M, Huang L. Manipulating Optical Scattering of Quasi-BIC in Dielectric Metasurface with Off-Center Hole. NANOMATERIALS 2021; 12:nano12010054. [PMID: 35010004 PMCID: PMC8746985 DOI: 10.3390/nano12010054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 12/19/2021] [Accepted: 12/21/2021] [Indexed: 01/08/2023]
Abstract
Bound states in the continuum (BICs) correspond to a particular leaky mode with an infinitely large quality-factor (Q-factor) located within the continuum spectrum. To date, most of the research work reported focuses on the BIC-enhanced light matter interaction due to its extreme near-field confinement. Little attention has been paid to the scattering properties of the BIC mode. In this work, we numerically study the far-field radiation manipulation of BICs by exploring multipole interference. By simply breaking the symmetry of the silicon metasurface, an ideal BIC is converted to a quasi-BIC with a finite Q-factor, which is manifested by the Fano resonance in the transmission spectrum. We found that both the intensity and directionality of the far-field radiation pattern can not only be tuned by the asymmetric parameters but can also experience huge changes around the resonance. Even for the same structure, two quasi-BICs show a different radiation pattern evolution when the asymmetric structure parameter d increases. It can be found that far-field radiation from one BIC evolves from electric-quadrupole-dominant radiation to toroidal-dipole-dominant radiation, whereas the other one shows electric-dipole-like radiation due to the interference of the magnetic dipole and electric quadrupole with the increasing asymmetric parameters. The result may find applications in high-directionality nonlinear optical devices and semiconductor lasers by using a quasi-BIC-based metasurface.
Collapse
Affiliation(s)
- Chaobiao Zhou
- College of Mechanical and Electronic Engineering, Guizhou Minzu University, Guiyang 550025, China; (T.P.); (J.H.); (M.F.)
- Correspondence: (C.Z.); (L.H.)
| | - Tianyao Pu
- College of Mechanical and Electronic Engineering, Guizhou Minzu University, Guiyang 550025, China; (T.P.); (J.H.); (M.F.)
| | - Jing Huang
- College of Mechanical and Electronic Engineering, Guizhou Minzu University, Guiyang 550025, China; (T.P.); (J.H.); (M.F.)
| | - Menghui Fan
- College of Mechanical and Electronic Engineering, Guizhou Minzu University, Guiyang 550025, China; (T.P.); (J.H.); (M.F.)
| | - Lujun Huang
- School of Engineering and Information Technology, University of New South Wales, Canberra 2602, Australia
- Correspondence: (C.Z.); (L.H.)
| |
Collapse
|
50
|
Cerjan A, Jörg C, Vaidya S, Augustine S, Benalcazar WA, Hsu CW, von Freymann G, Rechtsman MC. Observation of bound states in the continuum embedded in symmetry bandgaps. SCIENCE ADVANCES 2021; 7:eabk1117. [PMID: 34936454 PMCID: PMC8694597 DOI: 10.1126/sciadv.abk1117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In the past decade, symmetry-protected bound states in the continuum (BICs) have proven to be an important design principle for creating and enhancing devices reliant upon states with high-quality (Q) factors, such as sensors, lasers, and those for harmonic generation. However, as we show, current implementations of symmetry-protected BICs in photonic crystal slabs can only be found at the center of the Brillouin zone and below the Bragg diffraction limit, which fundamentally restricts their use to single-frequency applications. By microprinting a three-dimensional (3D) photonic crystal structure using two-photon polymerization, we demonstrate that this limitation can be overcome by altering the radiative environment surrounding the slab to be a 3D photonic crystal. This allows for the protection of a line of BICs by embedding it in a symmetry bandgap of the crystal. This concept substantially expands the design freedom available for developing next-generation devices with high-Q states.
Collapse
Affiliation(s)
- Alexander Cerjan
- Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM 87185, USA
- Corresponding author. (A.C.); (C.J.)
| | - Christina Jörg
- Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA
- Corresponding author. (A.C.); (C.J.)
| | - Sachin Vaidya
- Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA
| | - Shyam Augustine
- Physics Department and Research Center OPTIMAS, University of Kaiserslautern, D-67663 Kaiserslautern, Germany
| | - Wladimir A. Benalcazar
- Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA
| | - Chia Wei Hsu
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Georg von Freymann
- Physics Department and Research Center OPTIMAS, University of Kaiserslautern, D-67663 Kaiserslautern, Germany
- Fraunhofer Institute for Industrial Mathematics ITWM, 67663, Kaiserslautern, Germany
| | - Mikael C. Rechtsman
- Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA
| |
Collapse
|