1
|
Chen R, Luo YH, Long J, Shi B, Shen C, Liu J. Ultralow-Loss Integrated Photonics Enables Bright, Narrowband, Photon-Pair Sources. PHYSICAL REVIEW LETTERS 2024; 133:083803. [PMID: 39241729 DOI: 10.1103/physrevlett.133.083803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2024] [Accepted: 07/23/2024] [Indexed: 09/09/2024]
Abstract
Photon-pair sources are critical building blocks for photonic quantum systems. Leveraging Kerr nonlinearity and cavity-enhanced spontaneous four-wave mixing, chip-scale photon-pair sources can be created using microresonators built on photonic integrated circuit. For practical applications, a high microresonator quality factor Q is mandatory to magnify photon-pair sources' brightness and reduce their linewidth. The former is proportional to Q^{4}, while the latter is inversely proportional to Q. Here, we demonstrate an integrated, microresonator-based, narrowband photon-pair source. The integrated microresonator, made of silicon nitride and fabricated using a standard CMOS foundry process, features ultralow loss down to 0.03 dB/cm and intrinsic Q factor exceeding 10^{7}. The photon-pair source has brightness of 1.17×10^{9} Hz/mW^{2}/GHz and linewidth of 25.9 MHz, both of which are record values for silicon-photonics-based quantum light source. It further enables a heralded single-photon source with heralded second-order correlation g_{h}^{(2)}(0)=0.0037(5), as well as an energy-time entanglement source with a raw visibility of 0.973(9). Our work evidences the global potential of ultralow-loss integrated photonics to create novel quantum light sources and circuits, catalyzing efficient, compact, and robust interfaces to quantum communication and networks.
Collapse
Affiliation(s)
| | - Yi-Han Luo
- International Quantum Academy, Shenzhen 518048, China
| | - Jinbao Long
- International Quantum Academy, Shenzhen 518048, China
| | | | - Chen Shen
- International Quantum Academy, Shenzhen 518048, China
- Qaleido Photonics, Shenzhen 518048, China
| | | |
Collapse
|
2
|
Jin X, Lv Z, Yao L, Gong Q, Yang QF. Self-Suppressed Quantum-Limited Timing Jitter and Fundamental Noise Limit of Soliton Microcombs. PHYSICAL REVIEW LETTERS 2024; 133:073801. [PMID: 39213581 DOI: 10.1103/physrevlett.133.073801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 05/30/2024] [Accepted: 07/11/2024] [Indexed: 09/04/2024]
Abstract
Quantum-limited timing jitter of soliton microcombs has long been recognized as their fundamental noise limit. Here, we surpass such limit by utilizing dispersive wave dynamics in multimode microresonators. Through the viscous force provided by these dispersive waves, the quantum-limited timing jitter can be suppressed to a much lower level that forms the ultimate fundamental noise limit of soliton microcombs. Our findings enable coherence engineering of soliton microcombs in the quantum regime, providing critical guidelines for using soliton microcombs to synthesize ultralow-noise microwave and optical signals.
Collapse
Affiliation(s)
- Xing Jin
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Zhe Lv
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Lu Yao
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Qihuang Gong
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, 030006 Taiyuan, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
| | - Qi-Fan Yang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, 030006 Taiyuan, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
| |
Collapse
|
3
|
Flower CJ, Jalali Mehrabad M, Xu L, Moille G, Suarez-Forero DG, Örsel O, Bahl G, Chembo Y, Srinivasan K, Mittal S, Hafezi M. Observation of topological frequency combs. Science 2024; 384:1356-1361. [PMID: 38900874 DOI: 10.1126/science.ado0053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 05/09/2024] [Indexed: 06/22/2024]
Abstract
On-chip generation of optical frequency combs using nonlinear ring resonators has enabled numerous applications of combs that were otherwise limited to mode-locked lasers. Nevertheless, on-chip frequency combs have relied predominantly on single-ring resonators. In this study, we experimentally demonstrate the generation of a novel class of frequency combs, the topological frequency combs, in a two-dimensional lattice of hundreds of ring resonators that hosts fabrication-robust topological edge states with linear dispersion. By pumping these edge states, we demonstrate the generation of a nested frequency comb that shows oscillation of multiple edge state resonances across ≈40 longitudinal modes and is spatially confined at the lattice edge. Our results provide an opportunity to explore the interplay between topological physics and nonlinear frequency comb generation in a commercially available nanophotonic platform.
Collapse
Affiliation(s)
- Christopher J Flower
- Joint Quantum Institute, National Institute of Standards and Technology, University of Maryland, College Park, MD, USA
| | - Mahmoud Jalali Mehrabad
- Joint Quantum Institute, National Institute of Standards and Technology, University of Maryland, College Park, MD, USA
| | - Lida Xu
- Joint Quantum Institute, National Institute of Standards and Technology, University of Maryland, College Park, MD, USA
| | - Gregory Moille
- Joint Quantum Institute, National Institute of Standards and Technology, University of Maryland, College Park, MD, USA
| | - Daniel G Suarez-Forero
- Joint Quantum Institute, National Institute of Standards and Technology, University of Maryland, College Park, MD, USA
| | - Oğulcan Örsel
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Gaurav Bahl
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Yanne Chembo
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, USA
| | - Kartik Srinivasan
- Joint Quantum Institute, National Institute of Standards and Technology, University of Maryland, College Park, MD, USA
| | - Sunil Mittal
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, USA
| | - Mohammad Hafezi
- Joint Quantum Institute, National Institute of Standards and Technology, University of Maryland, College Park, MD, USA
| |
Collapse
|
4
|
Zhou C, He X, Xiao M, Ma D, Chen W, Zhou Z. Design of an on-chip wavelength conversion device assisted by an erbium-ytterbium co-doped waveguide amplifier. FRONTIERS OF OPTOELECTRONICS 2024; 17:16. [PMID: 38833110 DOI: 10.1007/s12200-024-00118-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 05/16/2024] [Indexed: 06/06/2024]
Abstract
In current documented studies, it has been observed that wavelength converters utilizing AlGaAsOI waveguides exhibit suboptimal on-chip wavelength conversion efficiency from the C-band to the 2 μm band, generally falling below -20.0 dB. To address this issue, we present a novel wavelength conversion device assisted by a waveguide amplifier, incorporating both AlGaAs wavelength converter and erbium-ytterbium co-doped waveguide amplifier, thereby achieving a notable conversion efficiency exceeding 0 dB. The noteworthy enhancement in efficiency can be attributed to the specific dispersion design of the AlGaAs wavelength converter, which enables an upsurge in conversion efficiency to -15.54 dB under 100 mW of pump power. Furthermore, the integration of an erbium-ytterbium co-doped waveguide amplifier facilitates a loss compensation of over 15 dB. Avoiding the use of external optical amplifiers, this device enables efficient and high-bandwidth wavelength conversion, showing promising applications in various fields, such as optical communication, sensing, imaging, and beyond.
Collapse
Affiliation(s)
- Chen Zhou
- School of Physical Sciences, University of Science and Technology of China, Hefei, 230026, China
- Aerospace Laser Technology and System Department, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China
| | - Xiwen He
- Aerospace Laser Technology and System Department, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China
| | - Mingyue Xiao
- Aerospace Laser Technology and System Department, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China
| | - Deyue Ma
- Aerospace Laser Technology and System Department, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China
| | - Weibiao Chen
- Aerospace Laser Technology and System Department, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China
| | - Zhiping Zhou
- Aerospace Laser Technology and System Department, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China.
- Hangzhou Aijie Optoelectronic Technology Co. Ltd., Hangzhou, 311400, China.
| |
Collapse
|
5
|
Geng Z, Cheng W, Yan Z, Yi Q, Liu Z, You M, Yu X, Wu P, Ding N, Tang X, Wang M, Shen L, Zhao Q. Low-loss tantalum pentoxide photonics with a CMOS-compatible process. OPTICS EXPRESS 2024; 32:12291-12302. [PMID: 38571056 DOI: 10.1364/oe.518545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 03/04/2024] [Indexed: 04/05/2024]
Abstract
We report a Ta2O5 photonic platform with a propagation loss of 0.49 dB/cm at 1550 nm, of 0.86 dB/cm at 780 nm, and of 3.76 dB/cm at 2000 nm. The thermal bistability measurement is conducted in the entire C-band for the first time to reveal the absorption loss of Ta2O5 waveguides, offering guidelines for further reduction of the waveguide loss. We also characterize the Ta2O5 waveguide temperature response, which shows favorable thermal stability. The fabrication process temperature is below 350°C, which is friendly to integration with active optoelectronic components.
Collapse
|
6
|
Morin TJ, Peters J, Li M, Guo J, Wan Y, Xiang C, Bowers JE. Coprocessed heterogeneous near-infrared lasers on thin-film lithium niobate. OPTICS LETTERS 2024; 49:1197-1200. [PMID: 38426972 DOI: 10.1364/ol.516486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024]
Abstract
Thin-film lithium niobate (TFLN) is an attractive platform for photonic applications on account of its wide bandgap, its large electro-optic coefficient, and its large nonlinearity. Since these characteristics are used in systems that require a coherent light source, size, weight, power, and cost can be reduced and reliability enhanced by combining TFLN processing and heterogeneous laser fabrication. Here, we report the fabrication of laser devices on a TFLN wafer and also the coprocessing of five different GaAs-based III-V epitaxial structures, including InGaAs quantum wells and InAs quantum dots. Lasing is observed at wavelengths near 930, 1030, and 1180 nm, which, if frequency-doubled using TFLN, would produce blue, green, and orange visible light. A single-sided power over 25 mW is measured with an integrating sphere.
Collapse
|
7
|
Abdollahi S, Ladouce M, Marin-Palomo P, Virte M. Agile THz-range spectral multiplication of frequency combs using a multi-wavelength laser. Nat Commun 2024; 15:1305. [PMID: 38346979 PMCID: PMC10861570 DOI: 10.1038/s41467-024-45610-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 01/30/2024] [Indexed: 02/15/2024] Open
Abstract
A breakthrough technology, on-chip frequency comb sources offer broadband combs while being compact, energy-efficient, and cost-effective solutions for various applications from lidar to telecommunications. Yet, these sources encounter a fundamental trade-off between controllability and bandwidth: broadband combs, generated in microresonators, lack free-spectral range or spectral envelope control, while combs generated with electro-optic modulators can be carefully tailored but are limited in bandwidth. Here, we overcome this trade-off through agile spectral multiplication of narrowband combs. Exploiting the nonlinear dynamics of a multi-wavelength laser under modulated optical injection, we achieve spectral multiplication at frequency offsets from 26 GHz to 1.3 THz. Moreover, on-chip control allows for nano-second switching of the frequency offset. Compatible with generic platforms, our approach can be scaled up to cover several THz. When combined with THz photomixers, our system could enable low-cost, compact, and power-efficient THz comb sources, paving the way towards a new generation of THz applications.
Collapse
Affiliation(s)
- Shahab Abdollahi
- Brussels Photonics Team (B-PHOT), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussel, Belgium.
| | - Mathieu Ladouce
- Brussels Photonics Team (B-PHOT), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussel, Belgium
| | - Pablo Marin-Palomo
- Brussels Photonics Team (B-PHOT), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussel, Belgium
| | - Martin Virte
- Brussels Photonics Team (B-PHOT), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050, Brussel, Belgium.
| |
Collapse
|
8
|
Xie Z, Jia S, Shao W, Han X, Su Y, Meng J, Gao D, Wang W, Xie X. Near-noiseless and small-footprint phase sensitive optical parametric amplifier using AlGaAs-on-insulator waveguides. APPLIED OPTICS 2023; 62:7233-7239. [PMID: 37855579 DOI: 10.1364/ao.501279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 08/29/2023] [Indexed: 10/20/2023]
Abstract
Phase sensitive amplifiers (PSAs) based on optical parametric amplification feature near noiseless amplification, which is of considerable benefit for improving the performance of optical communication systems. Currently, the majority of research on PSAs is carried out on the basis of highly nonlinear fibers or periodically poled lithium niobite waveguides, with the impediments of being susceptible to environmental interference and requiring complex temperature control systems to maintain quasi-phase matching conditions, respectively. Here, a near-noiseless and small-footprint PSA based on dispersion-engineered AlGaAs-on-insulator (AlGaAsOI) waveguides is proposed and demonstrated theoretically. The phase-dependent gain and the phase-to-phase transfer function of the PSA are calculated to analyze its characteristics. Furthermore, we investigate in detail the effects of linear loss, nonlinear coefficient, and pump power on the PSA gain and noise figure (NF) in AlGaAsOI waveguides. The results show that a PSA based on an AlGaAsOI waveguide is feasible with a maximum phase sensitive gain of 33 dB, achieving an NF of less than 1 dB over a gain bandwidth of 245 nm with a gain of >15d B, which completely covers the S + C + L band. This investigation is worthwhile for noiseless PSAs on photonic integrated chips, which are promising for low-noise optical amplification, multifunctional photonic integrated chips, quantum communication, and spectroscopy, and as a reference for low-noise PSAs depending on the third-order nonlinearity, χ (3), of the waveguide material.
Collapse
|
9
|
Xie J, Wang Y, Kang H, Cheng J, Shen X. Hydrophobic Silica Microcavities with Sustainable Nonlinear Photonic Performance. ACS APPLIED MATERIALS & INTERFACES 2023; 15:41067-41072. [PMID: 37603696 DOI: 10.1021/acsami.3c06300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
Ultrahigh quality factor (Q) microcavities have been emerging as appealing compact photonic platforms for various applications. The Q factor plays a critical role in determining the nonlinear optical performance of a microcavity. However, a silica microcavity suffers from severe degradation of its Q value over time during storage or use in air due to the accumulating surface absorption loss, which would deteriorate their nonlinear photonic performance. Here, we report a new type of ultrahigh Q silica microcavity that effectively prevents Q degradation over time. The Q values of the devices remain unchanged over time under storage in air. Optical frequency combs are generated with sustainable ultralow threshold performance over the course of time from the devices in open air. This approach would greatly facilitate ultrahigh Q silica-based photonic devices for next generation photonic applications.
Collapse
Affiliation(s)
- Jiadu Xie
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yang Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Hui Kang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jinsong Cheng
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xiaoqin Shen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| |
Collapse
|
10
|
Wu L, Xie W, Chen HJ, Colburn K, Xiang C, Chang L, Jin W, Liu JY, Yu Y, Yamamoto Y, Bowers JE, Suh MG, Vahala KJ. AlGaAs soliton microcombs at room temperature. OPTICS LETTERS 2023; 48:3853-3856. [PMID: 37527066 DOI: 10.1364/ol.484552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 05/21/2023] [Indexed: 08/03/2023]
Abstract
Soliton mode locking in high-Q microcavities provides a way to integrate frequency comb systems. Among material platforms, AlGaAs has one of the largest optical nonlinearity coefficients, and is advantageous for low-pump-threshold comb generation. However, AlGaAs also has a very large thermo-optic effect that destabilizes soliton formation, and femtosecond soliton pulse generation has only been possible at cryogenic temperatures. Here, soliton generation in AlGaAs microresonators at room temperature is reported for the first time, to the best of our knowledge. The destabilizing thermo-optic effect is shown to instead provide stability in the high-repetition-rate soliton regime (corresponding to a large, normalized second-order dispersion parameter D2/κ). Single soliton and soliton crystal generation with sub-milliwatt optical pump power are demonstrated. The generality of this approach is verified in a high-Q silica microtoroid where manual tuning into the soliton regime is demonstrated. Besides the advantages of large optical nonlinearity, these AlGaAs devices are natural candidates for integration with semiconductor pump lasers. Furthermore, the approach should generalize to any high-Q resonator material platform.
Collapse
|
11
|
Shen B, Shu H, Xie W, Chen R, Liu Z, Ge Z, Zhang X, Wang Y, Zhang Y, Cheng B, Yu S, Chang L, Wang X. Harnessing microcomb-based parallel chaos for random number generation and optical decision making. Nat Commun 2023; 14:4590. [PMID: 37524697 PMCID: PMC10390475 DOI: 10.1038/s41467-023-40152-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 07/14/2023] [Indexed: 08/02/2023] Open
Abstract
Optical chaos is vital for various applications such as private communication, encryption, anti-interference sensing, and reinforcement learning. Chaotic microcombs have emerged as promising sources for generating massive optical chaos. However, their inter-channel correlation behavior remains elusive, limiting their potential for on-chip parallel chaotic systems with high throughput. In this study, we present massively parallel chaos based on chaotic microcombs and high-nonlinearity AlGaAsOI platforms. We demonstrate the feasibility of generating parallel chaotic signals with inter-channel correlation <0.04 and a high random number generation rate of 3.84 Tbps. We further show the application of our approach by demonstrating a 15-channel integrated random bit generator with a 20 Gbps channel rate using silicon photonic chips. Additionally, we achieved a scalable decision-making accelerator for up to 256-armed bandit problems. Our work opens new possibilities for chaos-based information processing systems using integrated photonics, and potentially can revolutionize the current architecture of communication, sensing and computations.
Collapse
Affiliation(s)
- Bitao Shen
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China
| | - Haowen Shu
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China.
| | - Weiqiang Xie
- Department of Electronic Engineering, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Ruixuan Chen
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China
| | - Zhi Liu
- State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083, Beijing, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Zhangfeng Ge
- Peking University Yangtze Delta Institute of Optoelectronics, 226010, Nantong, China
| | - Xuguang Zhang
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China
| | - Yimeng Wang
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China
| | - Yunhao Zhang
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China
| | - Buwen Cheng
- State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083, Beijing, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Shaohua Yu
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China
- Peng Cheng Laboratory, 518055, Shenzhen, China
| | - Lin Chang
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China.
- Frontiers Science Center for Nano-optoelectronics, Peking University, 100871, Beijing, China.
| | - Xingjun Wang
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China.
- Peking University Yangtze Delta Institute of Optoelectronics, 226010, Nantong, China.
- Peng Cheng Laboratory, 518055, Shenzhen, China.
- Frontiers Science Center for Nano-optoelectronics, Peking University, 100871, Beijing, China.
| |
Collapse
|
12
|
Liu P, Wen H, Ren L, Shi L, Zhang X. χ (2) nonlinear photonics in integrated microresonators. FRONTIERS OF OPTOELECTRONICS 2023; 16:18. [PMID: 37460874 DOI: 10.1007/s12200-023-00073-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 05/22/2023] [Indexed: 07/20/2023]
Abstract
Second-order (χ(2)) optical nonlinearity is one of the most common mechanisms for modulating and generating coherent light in photonic devices. Due to strong photon confinement and long photon lifetime, integrated microresonators have emerged as an ideal platform for investigation of nonlinear optical effects. However, existing silicon-based materials lack a χ(2) response due to their centrosymmetric structures. A variety of novel material platforms possessing χ(2) nonlinearity have been developed over the past two decades. This review comprehensively summarizes the progress of second-order nonlinear optical effects in integrated microresonators. First, the basic principles of χ(2) nonlinear effects are introduced. Afterward, we highlight the commonly used χ(2) nonlinear optical materials, including their material properties and respective functional devices. We also discuss the prospects and challenges of utilizing χ(2) nonlinearity in the field of integrated microcavity photonics.
Collapse
Affiliation(s)
- Pengfei Liu
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Hao Wen
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Linhao Ren
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Lei Shi
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China.
- Optics Valley Laboratory, Wuhan, 430074, China.
| | - Xinliang Zhang
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
- Optics Valley Laboratory, Wuhan, 430074, China
| |
Collapse
|
13
|
Kamel AN, Pu M, Yvind K. Surface defect effects in AlGaAs-on-Insulator photonic waveguides. OPTICS EXPRESS 2023; 31:20424-20439. [PMID: 37381437 DOI: 10.1364/oe.490043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 05/18/2023] [Indexed: 06/30/2023]
Abstract
We report on our study of optical losses due to sub-band-gap absorption in AlGaAs-on-Insulator photonic nano-waveguides. Via numerical simulations and optical pump-probe measurements, we find that there is significant free carrier capture and release by defect states. Our measurements of the absorption of these defects point to the prevalence of the well-studied EL2 defect, which forms near oxidized (Al)GaAs surfaces. We couple our experimental data with numerical and analytical models to extract important parameters related to surface states, namely the coefficients of absorption, surface trap density and free carrier lifetime.
Collapse
|
14
|
He Z, Sun C, Xiong B, Wang J, Hao Z, Wang L, Han Y, Li H, Gan L, Luo Y. Simple and accurate dispersion measurement of GaN microresonators with a fiber ring. OPTICS LETTERS 2023; 48:2182-2185. [PMID: 37058672 DOI: 10.1364/ol.485023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/17/2023] [Indexed: 06/19/2023]
Abstract
The dispersion characteristics of a microresonator are important for applications in nonlinear optics, and precise measurement of the dispersion profile is crucial to device design and optimization. Here we demonstrate the dispersion measurement of high-quality-factor gallium nitride (GaN) microrings by a single-mode fiber ring, which is simple and convenient to access. Once the dispersion parameters of the fiber ring have been determined by the opto-electric modulation method, the dispersion can be obtained from the microresonator dispersion profile by polynomial fitting. To further verify the accuracy of the proposed method, the dispersion of the GaN microrings is also evaluated with frequency comb-based spectroscopy. Dispersion profiles obtained with both methods are in good agreement with simulations based on the finite element method.
Collapse
|
15
|
Lao C, Jin X, Chang L, Wang H, Lv Z, Xie W, Shu H, Wang X, Bowers JE, Yang QF. Quantum decoherence of dark pulses in optical microresonators. Nat Commun 2023; 14:1802. [PMID: 37002215 PMCID: PMC10066214 DOI: 10.1038/s41467-023-37475-z] [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: 09/28/2022] [Accepted: 03/16/2023] [Indexed: 04/03/2023] Open
Abstract
Quantum fluctuations disrupt the cyclic motions of dissipative Kerr solitons (DKSs) in nonlinear optical microresonators and consequently cause timing jitter of the emitted pulse trains. This problem is translated to the performance of several applications that employ DKSs as compact frequency comb sources. Recently, device manufacturing and noise reduction technologies have advanced to unveil the quantum properties of DKSs. Here we investigate the quantum decoherence of DKSs existing in normal-dispersion microresonators known as dark pulses. By virtue of the very large material nonlinearity, we directly observe the quantum decoherence of dark pulses in an AlGaAs-on-insulator microresonator, and the underlying dynamical processes are resolved by injecting stochastic photons into the microresonators. Moreover, phase correlation measurements show that the uniformity of comb spacing of quantum-limited dark pulses is better than 1.2 × 10-16 and 2.5 × 10-13 when normalized to the optical carrier frequencies and repetition frequencies, respectively. Comparing DKSs generated in different material platforms explicitly confirms the advantages of dark pulses over bright solitons in terms of quantum-limited coherence. Our work establishes a critical performance assessment of DKSs, providing guidelines for coherence engineering of chip-scale optical frequency combs.
Collapse
Affiliation(s)
- Chenghao Lao
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China
| | - Xing Jin
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China
| | - Lin Chang
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China
| | - Heming Wang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Zhe Lv
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China
| | - Weiqiang Xie
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA, 93106, USA
- State Key Lab of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Haowen Shu
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China
| | - Xingjun Wang
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, 100871, Beijing, China
| | - John E Bowers
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA, 93106, USA.
| | - Qi-Fan Yang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China.
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, China.
| |
Collapse
|
16
|
Abstract
The emergence of parallel convolution-operation technology has substantially powered the complexity and functionality of optical neural networks (ONN) by harnessing the dimension of optical wavelength. However, this advanced architecture faces remarkable challenges in high-level integration and on-chip operation. In this work, convolution based on time-wavelength plane stretching approach is implemented on a microcomb-driven chip-based photonic processing unit (PPU). To support the operation of this processing unit, we develop a dedicated control and operation protocol, leading to a record high weight precision of 9 bits. Moreover, the compact architecture and high data loading speed enable a preeminent photonic-core compute density of over 1 trillion of operations per second per square millimeter (TOPS mm-2). Two proof-of-concept experiments are demonstrated, including image edge detection and handwritten digit recognition, showing comparable processing capability compared to that of a digital computer. Due to the advanced performance and the great scalability, this parallel photonic processing unit can potentially revolutionize sophisticated artificial intelligence tasks including autonomous driving, video action recognition and image reconstruction.
Collapse
|
17
|
Wang C, Li J, Yi A, Fang Z, Zhou L, Wang Z, Niu R, Chen Y, Zhang J, Cheng Y, Liu J, Dong CH, Ou X. Soliton formation and spectral translation into visible on CMOS-compatible 4H-silicon-carbide-on-insulator platform. LIGHT, SCIENCE & APPLICATIONS 2022; 11:341. [PMID: 36473842 PMCID: PMC9726892 DOI: 10.1038/s41377-022-01042-w] [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: 06/24/2022] [Revised: 11/10/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Recent advancements in integrated soliton microcombs open the route to a wide range of chip-based communication, sensing, and metrology applications. The technology translation from laboratory demonstrations to real-world applications requires the fabrication process of photonics chips to be fully CMOS-compatible, such that the manufacturing can take advantage of the ongoing evolution of semiconductor technology at reduced cost and with high volume. Silicon nitride has become the leading CMOS platform for integrated soliton devices, however, it is an insulator and lacks intrinsic second-order nonlinearity for electro-optic modulation. Other materials have emerged such as AlN, LiNbO3, AlGaAs and GaP that exhibit simultaneous second- and third-order nonlinearities. Here, we show that silicon carbide (SiC) -- already commercially deployed in nearly ubiquitous electrical power devices such as RF electronics, MOSFET, and MEMS due to its wide bandgap properties, excellent mechanical properties, piezoelectricity and chemical inertia -- is a new competitive CMOS-compatible platform for nonlinear photonics. High-quality-factor microresonators (Q = 4 × 106) are fabricated on 4H-SiC-on-insulator thin films, where a single soliton microcomb is generated. In addition, we observe wide spectral translation of chaotic microcombs from near-infrared to visible due to the second-order nonlinearity of SiC. Our work highlights the prospects of SiC for future low-loss integrated nonlinear and quantum photonics that could harness electro-opto-mechanical interactions on a monolithic platform.
Collapse
Affiliation(s)
- Chengli Wang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- The Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Jin Li
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, 230026, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 230026, Hefei, China
| | - Ailun Yi
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
| | - Zhiwei Fang
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
| | - Liping Zhou
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- The Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Zhe Wang
- The Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, China
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
| | - Rui Niu
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, 230026, Hefei, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 230026, Hefei, China
| | - Yang Chen
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- The Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Jiaxiang Zhang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China
- The Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Ya Cheng
- The Extreme Optoelectromechanics Laboratory (XXL), School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
- State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 201800, Shanghai, China
| | - Junqiu Liu
- International Quantum Academy, 518048, Shenzhen, China.
- Hefei National Laboratory, University of Science and Technology of China, Hefei, 230026, China.
| | - Chun-Hua Dong
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, 230026, Hefei, China.
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, 230026, Hefei, China.
| | - Xin Ou
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 200050, Shanghai, China.
- The Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049, Beijing, China.
| |
Collapse
|
18
|
A photonic integrated continuous-travelling-wave parametric amplifier. Nature 2022; 612:56-61. [DOI: 10.1038/s41586-022-05329-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/07/2022] [Indexed: 12/05/2022]
|
19
|
Chen X, Sun S, Ji W, Ding X, Gao Y, Liu T, Wen J, Guo H, Wang T. Soliton Microcomb on Chip Integrated Si3N 4 Microresonators with Power Amplification in Erbium-Doped Optical Mono-Core Fiber. MICROMACHINES 2022; 13:2125. [PMID: 36557424 PMCID: PMC9785997 DOI: 10.3390/mi13122125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/27/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
Soliton microcombs, offering large mode spacing and broad bandwidth, have enabled a variety of advanced applications, particularly for telecommunications, photonic data center, and optical computation. Yet, the absolute power of microcombs remains insufficient, such that optical power amplification is always required. Here, we demonstrate a combined technique to access power-sufficient optical microcombs, with a photonic-integrated soliton microcomb and home-developed erbium-doped gain fiber. The soliton microcomb is generated in an integrated Si3N4 microresonator chip, which serves as a full-wave probing signal for power amplification. After the amplification, more than 40 comb modes, with 115-GHz spacing, reach the onset power level of >−10 dBm, which is readily available for parallel telecommunications , among other applications.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Jianxiang Wen
- Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication, Shanghai University, Shanghai 200444, China
| | - Hairun Guo
- Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication, Shanghai University, Shanghai 200444, China
| | | |
Collapse
|
20
|
Wang X, Xie P, Chen B, Zhang X. Chip-Based High-Dimensional Optical Neural Network. NANO-MICRO LETTERS 2022; 14:221. [PMID: 36374430 PMCID: PMC9663775 DOI: 10.1007/s40820-022-00957-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/03/2022] [Indexed: 05/16/2023]
Abstract
Parallel multi-thread processing in advanced intelligent processors is the core to realize high-speed and high-capacity signal processing systems. Optical neural network (ONN) has the native advantages of high parallelization, large bandwidth, and low power consumption to meet the demand of big data. Here, we demonstrate the dual-layer ONN with Mach-Zehnder interferometer (MZI) network and nonlinear layer, while the nonlinear activation function is achieved by optical-electronic signal conversion. Two frequency components from the microcomb source carrying digit datasets are simultaneously imposed and intelligently recognized through the ONN. We successfully achieve the digit classification of different frequency components by demultiplexing the output signal and testing power distribution. Efficient parallelization feasibility with wavelength division multiplexing is demonstrated in our high-dimensional ONN. This work provides a high-performance architecture for future parallel high-capacity optical analog computing.
Collapse
Affiliation(s)
- Xinyu Wang
- School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Peng Xie
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
| | - Bohan Chen
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Xingcai Zhang
- School of Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA.
| |
Collapse
|
21
|
MacFarlane N, Schreyer-Miller A, Foster MA, Houck WD, Foster AC. Niobium-tantalum oxide as a material platform for linear and nonlinear integrated photonics. OPTICS EXPRESS 2022; 30:42155-42167. [PMID: 36366674 PMCID: PMC9662598 DOI: 10.1364/oe.473756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/01/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Here we realize the first reported integrated photonic devices fabricated using sputtered niobium-tantalum oxide films. Sputtered niobium-tantalum oxide films are highly promising for integrated photonics as they are scalable to high volume manufacturing, possess high refractive index, and are transparent in the ultraviolet through near infrared wavelength range. At a wavelength near 1550 nm, we observe propagation losses as low as 0.47 dB/cm in waveguides and ring resonators with resonator quality factors as high as 860,000. We also characterize the nonlinear performance of these films and find a Kerr coefficient (n2) of 1.2 ( ± 0.2) × 10-18 m2/W. With this high Kerr coefficient we demonstrate optical parametric oscillation in a ring resonator and supercontinuum generation in a waveguide.
Collapse
Affiliation(s)
- Neil MacFarlane
- Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | | | - Mark A. Foster
- Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - William D. Houck
- VIAVI Solutions Inc., 1402 Mariner Way, Santa Rosa, CA 94507, USA
| | - Amy C. Foster
- Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| |
Collapse
|
22
|
Liu M, Dang Y, Huang H, Lu Z, Wang Y, Cai Y, Zhao W. Loss modulation assisted solitonic pulse excitation in Kerr resonators with normal group velocity dispersion. OPTICS EXPRESS 2022; 30:30176-30186. [PMID: 36242126 DOI: 10.1364/oe.464145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/18/2022] [Indexed: 06/16/2023]
Abstract
We demonstrate an emergent solitonic pulse generation approach exploiting the externally introduced or intrinsic loss fluctuation effects. Single or multiple pulses are accessible via self-evolution of the system in the red, blue detuning regime or even on resonance with loss perturbation. The potential well caused by the loss profile not only traps the generated pulses, but also helps to suppress the drift regarding high-order dispersion. Breathing dynamics is also observed with high driving force, which can be transferred to stable state by backward tuning the pump detuning. We further investigate the intrinsic free carrier absorption, recognized as unfavored effect traditionally, could be an effective factor for pulse excitation through the time-variant loss fluctuation in normal dispersion microresonators. Pulse excitation dynamics associated with physical parameters are also discussed. These findings could establish a feasible path for stable localized structures and Kerr microcombs generation in potential platforms.
Collapse
|
23
|
Zeng D, Liu Q, Mei C, Li H, Huang Q, Zhang X. Demonstration of Ultra-High-Q Silicon Microring Resonators for Nonlinear Integrated Photonics. MICROMACHINES 2022; 13:mi13071155. [PMID: 35888971 PMCID: PMC9322067 DOI: 10.3390/mi13071155] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/15/2022] [Accepted: 07/19/2022] [Indexed: 11/25/2022]
Abstract
A reflowing photoresist and oxidation smoothing process is used to fabricate ultra-high-Q silicon microring resonators based on multimode rib waveguides. Over a wide range of wavelengths near 1550 nm, the average Q-factor of a ring with 1.2-μm-wide waveguides reaches up to 1.17 × 106, with a waveguide loss of approximately 0.28 dB/cm. For a resonator with 1.5-μm-wide waveguides, the average Q-factor reaches 1.20 × 106, and the waveguide loss is 0.27 dB/cm. Moreover, we theoretically and experimentally show that a reduction in the waveguide loss significantly improves the conversion efficiency of four-wave mixing. A high four-wave mixing conversion efficiency of −17.0 dB is achieved at a pump power of 6.50 dBm.
Collapse
|
24
|
Cui X, Du M, Das S, Yoon HH, Pelgrin VY, Li D, Sun Z. On-chip photonics and optoelectronics with a van der Waals material dielectric platform. NANOSCALE 2022; 14:9459-9465. [PMID: 35735657 PMCID: PMC9261272 DOI: 10.1039/d2nr01042a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/29/2022] [Indexed: 06/15/2023]
Abstract
During the last few decades, photonic integrated circuits have increased dramatically, facilitating many high-performance applications, such as on-chip sensing, data processing, and inter-chip communications. The currently dominating material platforms (i.e., silicon, silicon nitride, lithium niobate, and indium phosphide), which have exhibited great application successes, however, suffer from their own disadvantages, such as the indirect bandgap of silicon for efficient light emission, and the compatibility challenges of indium phosphide with the silicon industry. Here, we report a new dielectric platform using nanostructured bulk van der Waals materials. On-chip light propagation, emission, and detection are demonstrated by taking advantage of different van der Waals materials. Low-loss passive waveguides with MoS2 and on-chip light sources and photodetectors with InSe have been realised. Our proof-of-concept demonstration of passive and active on-chip photonic components endorses van der Waals materials for offering a new dielectric platform with a large material-selection degree of freedom and unique properties toward close-to-atomic scale manufacture of on-chip photonic and optoelectronic devices.
Collapse
Affiliation(s)
- Xiaoqi Cui
- Department of Electronics and Nanoengineering, Aalto University, Espoo FI-02150, Finland.
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, Espoo FI-00076, Finland
| | - Mingde Du
- Department of Electronics and Nanoengineering, Aalto University, Espoo FI-02150, Finland.
| | - Susobhan Das
- Department of Electronics and Nanoengineering, Aalto University, Espoo FI-02150, Finland.
| | - Hoon Hahn Yoon
- Department of Electronics and Nanoengineering, Aalto University, Espoo FI-02150, Finland.
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, Espoo FI-00076, Finland
| | - Vincent Yves Pelgrin
- Department of Electronics and Nanoengineering, Aalto University, Espoo FI-02150, Finland.
- Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, 91120, Palaiseau, France
| | - Diao Li
- Department of Electronics and Nanoengineering, Aalto University, Espoo FI-02150, Finland.
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, Espoo FI-00076, Finland
| | - Zhipei Sun
- Department of Electronics and Nanoengineering, Aalto University, Espoo FI-02150, Finland.
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, Espoo FI-00076, Finland
| |
Collapse
|
25
|
Mobini E, Espinosa DHG, Vyas K, Dolgaleva K. AlGaAs Nonlinear Integrated Photonics. MICROMACHINES 2022; 13:mi13070991. [PMID: 35888808 PMCID: PMC9323658 DOI: 10.3390/mi13070991] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 06/06/2022] [Accepted: 06/13/2022] [Indexed: 01/18/2023]
Abstract
Practical applications implementing integrated photonic circuits can benefit from nonlinear optical functionalities such as wavelength conversion, all-optical signal processing, and frequency-comb generation, among others. Numerous nonlinear waveguide platforms have been explored for these roles; the group of materials capable of combining both passive and active functionalities monolithically on the same chip is III–V semiconductors. AlGaAs is the most studied III–V nonlinear waveguide platform to date; it exhibits both second- and third-order optical nonlinearity and can be used for a wide range of integrated nonlinear photonic devices. In this review, we conduct an extensive overview of various AlGaAs nonlinear waveguide platforms and geometries, their nonlinear optical performances, as well as the measured values and wavelength dependencies of their effective nonlinear coefficients. Furthermore, we highlight the state-of-the-art achievements in the field, among which are efficient tunable wavelength converters, on-chip frequency-comb generation, and ultra-broadband on-chip supercontinuum generation. Moreover, we overview the applications in development where AlGaAs nonlinear functional devices aspire to be the game-changers. Among such applications, there is all-optical signal processing in optical communication networks and integrated quantum photonic circuits.
Collapse
Affiliation(s)
- Ehsan Mobini
- Department of Physics, University of Ottawa, Ottawa, ON K1N 6N5, Canada;
| | - Daniel H. G. Espinosa
- School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (D.H.G.E.); (K.V.)
| | - Kaustubh Vyas
- School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (D.H.G.E.); (K.V.)
| | - Ksenia Dolgaleva
- Department of Physics, University of Ottawa, Ottawa, ON K1N 6N5, Canada;
- School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (D.H.G.E.); (K.V.)
- Correspondence:
| |
Collapse
|
26
|
Shu H, Chang L, Tao Y, Shen B, Xie W, Jin M, Netherton A, Tao Z, Zhang X, Chen R, Bai B, Qin J, Yu S, Wang X, Bowers JE. Microcomb-driven silicon photonic systems. Nature 2022; 605:457-463. [PMID: 35585341 PMCID: PMC9117125 DOI: 10.1038/s41586-022-04579-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 02/24/2022] [Indexed: 11/27/2022]
Abstract
Microcombs have sparked a surge of applications over the past decade, ranging from optical communications to metrology1-4. Despite their diverse deployment, most microcomb-based systems rely on a large amount of bulky elements and equipment to fulfil their desired functions, which is complicated, expensive and power consuming. By contrast, foundry-based silicon photonics (SiPh) has had remarkable success in providing versatile functionality in a scalable and low-cost manner5-7, but its available chip-based light sources lack the capacity for parallelization, which limits the scope of SiPh applications. Here we combine these two technologies by using a power-efficient and operationally simple aluminium-gallium-arsenide-on-insulator microcomb source to drive complementary metal-oxide-semiconductor SiPh engines. We present two important chip-scale photonic systems for optical data transmission and microwave photonics, respectively. A microcomb-based integrated photonic data link is demonstrated, based on a pulse-amplitude four-level modulation scheme with a two-terabit-per-second aggregate rate, and a highly reconfigurable microwave photonic filter with a high level of integration is constructed using a time-stretch approach. Such synergy of a microcomb and SiPh integrated components is an essential step towards the next generation of fully integrated photonic systems.
Collapse
Affiliation(s)
- Haowen Shu
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China
| | - Lin Chang
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Yuansheng Tao
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China
| | - Bitao Shen
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China
| | - Weiqiang Xie
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Ming Jin
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China
| | - Andrew Netherton
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Zihan Tao
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China
| | - Xuguang Zhang
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China
| | - Ruixuan Chen
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China
| | - Bowen Bai
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China
| | - Jun Qin
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China
| | - Shaohua Yu
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China
- Peng Cheng Laboratory, Shenzhen, China
| | - Xingjun Wang
- State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing, China.
- Peng Cheng Laboratory, Shenzhen, China.
- Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing, China.
| | - John E Bowers
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, USA.
| |
Collapse
|
27
|
Abstract
With the increasing demand for capacity in communications networks, the use of integrated photonics to transmit, process and manipulate digital and analog signals has been extensively explored. Silicon photonics, exploiting the complementary-metal-oxide-semiconductor (CMOS)-compatible fabrication technology to realize low-cost, robust, compact, and power-efficient integrated photonic circuits, is regarded as one of the most promising candidates for next-generation chip-scale information and communication technology (ICT). However, the electro-optic modulators, a key component of Silicon photonics, face challenges in addressing the complex requirements and limitations of various applications under state-of-the-art technologies. In recent years, the graphene EO modulators, promising small footprints, high temperature stability, cost-effective, scalable integration and a high speed, have attracted enormous interest regarding their hybrid integration with SiPh on silicon-on-insulator (SOI) chips. In this paper, we summarize the developments in the study of silicon-based graphene EO modulators, which covers the basic principle of a graphene EO modulator, the performance of graphene electro-absorption (EA) and electro-refractive (ER) modulators, as well as the recent advances in optical communications and microwave photonics (MWP). Finally, we discuss the emerging challenges and potential applications for the future practical use of silicon-based graphene EO modulators.
Collapse
|
28
|
Ultrastable microwave and soliton-pulse generation from fibre-photonic-stabilized microcombs. Nat Commun 2022; 13:381. [PMID: 35046409 PMCID: PMC8770478 DOI: 10.1038/s41467-022-27992-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 12/15/2021] [Indexed: 11/15/2022] Open
Abstract
The ability to generate lower-noise microwaves has greatly advanced high-speed, high-precision scientific and engineering fields. Microcombs have high potential for generating such low-noise microwaves from chip-scale devices. To realize an ultralow-noise performance over a wider Fourier frequency range and longer time scale, which is required for many high-precision applications, free-running microcombs must be locked to more stable reference sources. However, ultrastable reference sources, particularly optical cavity-based methods, are generally bulky, alignment-sensitive and expensive, and therefore forfeit the benefits of using chip-scale microcombs. Here, we realize compact and low-phase-noise microwave and soliton pulse generation by combining a silica-microcomb (with few-mm diameter) with a fibre-photonic-based timing reference (with few-cm diameter). An ultrastable 22-GHz microwave is generated with −110 dBc/Hz (−88 dBc/Hz) phase noise at 1-kHz (100-Hz) Fourier frequency and 10−13-level frequency instability within 1-s. This work shows the potential of fully packaged, palm-sized or smaller systems for generating both ultrastable soliton pulse trains and microwaves, thereby facilitating a wide range of field applications involving ultrahigh-stability microcombs. A compact yet high-performance stabilization method has been the missing ingredient for microcombs. Here, optical fibre is used for stabilizing microcombs, enabling the generation of ultrastable soliton pulses and microwaves from palm-sized platforms
Collapse
|
29
|
Nishimoto K, Minoshima K, Yasui T, Kuse N. Thermal control of a Kerr microresonator soliton comb via an optical sideband. OPTICS LETTERS 2022; 47:281-284. [PMID: 35030587 DOI: 10.1364/ol.448326] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
We report the thermal control of a dissipative Kerr microresonator soliton comb via an optical sideband generated from an electro-optic modulator. Same as the previous reports using an independent auxiliary laser, our sideband-based (S-B) auxiliary light also enables access to a stable soliton comb and reduces the phase noise of the soliton comb, greatly simplifying the set-up with an auxiliary laser. More importantly, because of the intrinsically high frequency/phase correlation between the pump and S-B auxiliary light, the detuning between the pump and resonance frequency is automatically almost fixed, which allows an 18 times larger "effective" soliton existence range than the conventional method using an independent auxiliary laser, as well as a scanning of the soliton comb of more than 10 GHz without using microheaters.
Collapse
|
30
|
Liu M, Shi W, Sun Q, Huang H, Lu Z, Wang Y, Cai Y, Wang C, Li Y, Zhao W. Free carrier induced dark pulse generation in microresonators. OPTICS LETTERS 2021; 46:4462-4465. [PMID: 34525022 DOI: 10.1364/ol.435668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/08/2021] [Indexed: 06/13/2023]
Abstract
We theoretically demonstrate a novel, to the best of our knowledge, mechanism for dark pulse excitation in normal dispersion microresonators exploiting free carrier dispersion and free carrier absorption effects due to multi-photon absorption. Dark pulses can be generated in the three- and four-photon absorption regimes in the presence or absence of external reverse bias to control the lifetime of free carriers, respectively. Direct generation of dark pulses is proven to be feasible in both regimes with a frequency fixed laser. The dynamics of their temporal and spectral evolution have also been investigated. Our findings establish a reliable path for dark pulse and Kerr microcomb generation in related platforms with simplified controlling and tuning techniques.
Collapse
|
31
|
Smirnov S, Andryushkov V, Podivilov E, Sturman B, Breunig I. Soliton based χ (2) combs in high-Q optical microresonators. OPTICS EXPRESS 2021; 29:27434-27449. [PMID: 34615159 DOI: 10.1364/oe.432529] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 07/29/2021] [Indexed: 06/13/2023]
Abstract
Investigations of the frequency combs in χ(3) microresonators have passed a critical point when the soliton based regimes are well established and realized on different platforms. For χ(2) microresonators, where the first harmonic (FH) and second harmonic (SH) envelopes are coupled via the SH generation and optical parametric oscillation, the comb-soliton studies are just starting. Here we report on a vast accessible dual χ(2) soliton-comb family in high-Q microresonators with the SH and FH combs centered at the pump frequency ωp and its half ωp/2. Vicinity of the point of equal FH and SH group velocities λc, available via proper radial poling, is found to be the most advantageous for the generation of spectrally broad dual FH-SH combs. Our predictions as applied to lithium niobate resonators include the dependence of comb and dissipative soliton parameters on the pump power, the deviation λp - λc, the modal quality factors and frequency detunings, and the necessary parameters of radial poling of the resonator. These predictions form a solid basis for the realization of χ(2) frequency combs.
Collapse
|
32
|
Kim C, Yvind K, Pu M. Suppression of avoided resonance crossing in microresonators. OPTICS LETTERS 2021; 46:3508-3511. [PMID: 34329211 DOI: 10.1364/ol.431667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 06/19/2021] [Indexed: 06/13/2023]
Abstract
Kerr frequency comb generation in microresonators is enabled by notable developments in fabrication technology and novel nonlinear material platforms. However, even in a low loss and highly nonlinear microresonator, the avoided resonance crossing may hamper reliable frequency comb generation. We present a method to suppress the avoided resonance crossing induced by polarization mode coupling. Our approach employs a filter waveguide coupled to a microring resonator for selective filtering of the TM00 mode while keeping the operational TE00 mode with low loss. We experimentally demonstrate an avoided-crossing-suppressed microresonator in the AlGaAs-on-insulator platform.
Collapse
|
33
|
Xiang C, Liu J, Guo J, Chang L, Wang RN, Weng W, Peters J, Xie W, Zhang Z, Riemensberger J, Selvidge J, Kippenberg TJ, Bowers JE. Laser soliton microcombs heterogeneously integrated on silicon. Science 2021; 373:99-103. [PMID: 34210884 DOI: 10.1126/science.abh2076] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/20/2021] [Indexed: 12/22/2022]
Abstract
Silicon photonics enables wafer-scale integration of optical functionalities on chip. Silicon-based laser frequency combs can provide integrated sources of mutually coherent laser lines for terabit-per-second transceivers, parallel coherent light detection and ranging, or photonics-assisted signal processing. We report heterogeneously integrated laser soliton microcombs combining both indium phospide/silicon (InP/Si) semiconductor lasers and ultralow-loss silicon nitride (Si3N4) microresonators on a monolithic silicon substrate. Thousands of devices can be produced from a single wafer by using complementary metal-oxide-semiconductor-compatible techniques. With on-chip electrical control of the laser-microresonator relative optical phase, these devices can output single-soliton microcombs with a 100-gigahertz repetition rate. Furthermore, we observe laser frequency noise reduction due to self-injection locking of the InP/Si laser to the Si3N4 microresonator. Our approach provides a route for large-volume, low-cost manufacturing of narrow-linewidth, chip-based frequency combs for next-generation high-capacity transceivers, data centers, space and mobile platforms.
Collapse
Affiliation(s)
- Chao Xiang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Junqiu Liu
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Joel Guo
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Lin Chang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Rui Ning Wang
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Wenle Weng
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jonathan Peters
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Weiqiang Xie
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Zeyu Zhang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Johann Riemensberger
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jennifer Selvidge
- Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Tobias J Kippenberg
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
| | - John E Bowers
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. .,Materials Department, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| |
Collapse
|
34
|
Boes A, Nguyen TG, Chang L, Bowers JE, Ren G, Mitchell A. Integrated photonic high extinction short and long pass filters based on lateral leakage. OPTICS EXPRESS 2021; 29:18905-18914. [PMID: 34154136 DOI: 10.1364/oe.426442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/24/2021] [Indexed: 06/13/2023]
Abstract
In this contribution we present a new approach to achieve high extinction short and long pass wavelength filters in the integrated photonic platform of lithium niobate on insulator. The filtering of unwanted wavelengths is achieved by employing lateral leakage and is related to the bound state in the continuum phenomenon. We show that it is possible to control the filter edge wavelength by adjusting the waveguide dimensions and that an extinction of hundreds of dB/cm is readily achievable. This enabled us to design a pump wavelength suppression of more than 100 dB in a 3.5 mm long waveguide, which is essential for on-chip integration of quantum-correlated photon pair sources. These findings pave the way to integrate multi wavelength experiments on chip for the next generation of photonic integrated circuits.
Collapse
|
35
|
Yang H, Brunel M, Vallet M, Zhang H, Zhao C. Optical frequency-to-time mapping using a phase-modulated frequency-shifting loop. OPTICS LETTERS 2021; 46:2336-2339. [PMID: 33988577 DOI: 10.1364/ol.425460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
A real-time spectral analysis is demonstrated experimentally with a frequency-shifting loop that includes an electro-optic phase modulator. When a single-frequency laser seeds the loop, pulse doublets are emitted if the integer Talbot condition is satisfied. With a polychromatic seed, frequency-to-time mapping is demonstrated, namely the temporal output of the loop maps the spectral power of the seed, with a resolution of 400 kHz. Due to the phase modulation function, the mapping is shown to be nonlinear. The results are in agreement with the theoretical predictions of [H. Yang et al., J. Opt. Soc. Am. B37, 3162 (2020)JOBPDE0740-322410.1364/JOSAB.389801]. The extension to integrated systems for applications is discussed.
Collapse
|
36
|
Liu J, Huang G, Wang RN, He J, Raja AS, Liu T, Engelsen NJ, Kippenberg TJ. High-yield, wafer-scale fabrication of ultralow-loss, dispersion-engineered silicon nitride photonic circuits. Nat Commun 2021; 12:2236. [PMID: 33863901 PMCID: PMC8052462 DOI: 10.1038/s41467-021-21973-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 02/17/2021] [Indexed: 01/19/2023] Open
Abstract
Low-loss photonic integrated circuits and microresonators have enabled a wide range of applications, such as narrow-linewidth lasers and chip-scale frequency combs. To translate these into a widespread technology, attaining ultralow optical losses with established foundry manufacturing is critical. Recent advances in integrated Si3N4 photonics have shown that ultralow-loss, dispersion-engineered microresonators with quality factors Q > 10 × 106 can be attained at die-level throughput. Yet, current fabrication techniques do not have sufficiently high yield and performance for existing and emerging applications, such as integrated travelling-wave parametric amplifiers that require meter-long photonic circuits. Here we demonstrate a fabrication technology that meets all requirements on wafer-level yield, performance and length scale. Photonic microresonators with a mean Q factor exceeding 30 × 106, corresponding to 1.0 dB m-1 optical loss, are obtained over full 4-inch wafers, as determined from a statistical analysis of tens of thousands of optical resonances, and confirmed via cavity ringdown with 19 ns photon storage time. The process operates over large areas with high yield, enabling 1-meter-long spiral waveguides with 2.4 dB m-1 loss in dies of only 5 × 5 mm2 size. Using a response measurement self-calibrated via the Kerr nonlinearity, we reveal that the intrinsic absorption-limited Q factor of our Si3N4 microresonators can exceed 2 × 108. This absorption loss is sufficiently low such that the Kerr nonlinearity dominates the microresonator's response even in the audio frequency band. Transferring this Si3N4 technology to commercial foundries can significantly improve the performance and capabilities of integrated photonics.
Collapse
Affiliation(s)
- Junqiu Liu
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Guanhao Huang
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Rui Ning Wang
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Jijun He
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Arslan S Raja
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Tianyi Liu
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Nils J Engelsen
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Tobias J Kippenberg
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
| |
Collapse
|
37
|
Poulvellarie N, Mas Arabi C, Ciret C, Combrié S, De Rossi A, Haelterman M, Raineri F, Kuyken B, Gorza SP, Leo F. Efficient type II second harmonic generation in an indium gallium phosphide on insulator wire waveguide aligned with a crystallographic axis. OPTICS LETTERS 2021; 46:1490-1493. [PMID: 33793472 DOI: 10.1364/ol.418064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
We theoretically and experimentally investigate type II second harmonic generation in III-V-on-insulator wire waveguides. We show that the propagation direction plays a crucial role and that longitudinal field components can be leveraged for robust and efficient conversion. We predict that the maximum theoretical conversion is larger than that of type I second harmonic generation for similar waveguide dimensions and reach an experimental conversion efficiency of 12%/W, limited by the propagation loss.
Collapse
|
38
|
Do IH, Kim D, Jeong D, Suk D, Kwon D, Kim J, Lee JH, Lee H. Self-stabilized soliton generation in a microresonator through mode-pulled Brillouin lasing. OPTICS LETTERS 2021; 46:1772-1775. [PMID: 33793540 DOI: 10.1364/ol.419137] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/07/2021] [Indexed: 06/12/2023]
Abstract
Reducing the complexity required for starting and maintaining a soliton state has been a major task to fully miniaturize soliton microcombs including the accompanying external operating systems. Here we experimentally examine the generative process of a self-stabilized soliton in which a continuous-wave pump detuned on the thermally stable blue side of a resonance generates a Brillouin lasing signal that relays the pump power to the soliton pulses via intracavity mode-coupling without breaking thermal self-stability. Based on a simple setup consisting of a free-running laser and a microcavity without any external feedback systems by virtue of internal thermal locking, single-soliton pulses of 11 GHz repetition rate were deterministically generated. We demonstrate that the single-soliton pulses can be passively maintained over several days in a laboratory environment with a phase noise performance of -137dBc/Hz at 100 kHz.
Collapse
|
39
|
Huang D, Abulnaga A, Welinski S, Raha M, Thompson JD, de Leon NP. Hybrid III-V diamond photonic platform for quantum nodes based on neutral silicon vacancy centers in diamond. OPTICS EXPRESS 2021; 29:9174-9189. [PMID: 33820350 DOI: 10.1364/oe.418081] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
Integrating atomic quantum memories based on color centers in diamond with on-chip photonic devices would enable entanglement distribution over long distances. However, efforts towards integration have been challenging because color centers can be highly sensitive to their environment, and their properties degrade in nanofabricated structures. Here, we describe a heterogeneously integrated, on-chip, III-V diamond platform designed for neutral silicon vacancy (SiV0) centers in diamond that circumvents the need for etching the diamond substrate. Through evanescent coupling to SiV0 centers near the surface of diamond, the platform will enable Purcell enhancement of SiV0 emission and efficient frequency conversion to the telecommunication C-band. The proposed structures can be realized with readily available fabrication techniques.
Collapse
|
40
|
Weng W, Kaszubowska-Anandarajah A, He J, Lakshmijayasimha PD, Lucas E, Liu J, Anandarajah PM, Kippenberg TJ. Gain-switched semiconductor laser driven soliton microcombs. Nat Commun 2021; 12:1425. [PMID: 33658513 PMCID: PMC7930029 DOI: 10.1038/s41467-021-21569-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 01/22/2021] [Indexed: 01/31/2023] Open
Abstract
Dissipative Kerr soliton generation using self-injection-locked III-V lasers has enabled fully integrated hybrid microcombs that operate in turnkey mode and can access microwave repetition rates. Yet, continuous-wave-driven soliton microcombs exhibit low energy conversion efficiency and high optical power threshold, especially when the repetition frequencies are within the microwave range that is convenient for direct detection with off-the-shelf electronics. Here, by actively switching the bias current of injection-locked III-V semiconductor lasers with switching frequencies in the X-band and K-band microwave ranges, we pulse-pump both crystalline and integrated microresonators with picosecond laser pulses, generating soliton microcombs with stable repetition rates and lowering the required average pumping power by one order of magnitude to a record-setting level of a few milliwatts. In addition, we unveil the critical role of the phase profile of the pumping pulses, and implement phase engineering on the pulsed pumping scheme, which allows for the robust generation and the stable trapping of solitons on intracavity pulse pedestals. Our work leverages the advantages of the gain switching and the pulse pumping techniques, and establishes the merits of combining distinct compact comb platforms that enhance the potential of energy-efficient chipscale microcombs.
Collapse
Affiliation(s)
- Wenle Weng
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
| | | | - Jijun He
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Prajwal D Lakshmijayasimha
- Photonics Systems and Sensing Laboratory, School of Electronic Engineering, Dublin City University, Glasnevin, Ireland
| | - Erwan Lucas
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
- Time and Frequency Division, NIST, Boulder, CO, USA
- Department of Physics, University of Colorado, Boulder, CO, USA
| | - Junqiu Liu
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Prince M Anandarajah
- Photonics Systems and Sensing Laboratory, School of Electronic Engineering, Dublin City University, Glasnevin, Ireland.
| | - Tobias J Kippenberg
- Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
| |
Collapse
|
41
|
Weng H, Liu J, Afridi AA, Li J, Dai J, Ma X, Zhang Y, Lu Q, Donegan JF, Guo W. Octave-spanning Kerr frequency comb generation with stimulated Raman scattering in an AlN microresonator. OPTICS LETTERS 2021; 46:540-543. [PMID: 33528404 DOI: 10.1364/ol.416460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
Octave-spanning optical frequency combs (OFCs) are essential for various applications, such as precision metrology and astrophysical spectrometer calibration. In this Letter, we demonstrate, for the first time to our knowledge, the generation of octave-spanning Kerr frequency combs ranging from 1150 to 2400 nm in aluminum nitride (AlN) microring resonators, by pumping the TM00 modes at 250 mW on-chip power. By simply adjusting the pump detuning, we observe the transition and coexistence of Kerr OFC and stimulated Raman scattering. For the TE00 mode in the same device, a broadband Raman-assisted frequency comb is demonstrated by adjusting the pump power and tuning. These results indicate a crucial development for the fundamentals of nonlinear dynamics and comb applications in AlN.
Collapse
|
42
|
Supercontinuum generation in dispersion engineered AlGaAs-on-insulator waveguides. Sci Rep 2021; 11:2052. [PMID: 33479455 PMCID: PMC7820398 DOI: 10.1038/s41598-021-81555-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/08/2021] [Indexed: 11/08/2022] Open
Abstract
The effect of engineering the dispersion of AlGaAs-on-insulator (AlGaAs-OI) waveguides on supercontinuum generation is investigated at telecom wavelengths. The pronounced effect the waveguide width has on the nonlinear dynamics governing the supercontinua is systematically analyzed and the coherence of the spectra verified with numerical simulations. Using dispersion engineered AlGaAs-OI waveguides, broadband supercontinua were readily obtained for pulse energies of [Formula: see text] and a device length of only 3 mm. The results presented here, further understanding of the design and fabrication of this novel platform and describe the soliton and dispersive wave dynamics responsible for supercontinuum generation. This study showcases the potential of AlGaAs-OI for exploring fundamental physics and realizing highly efficient, compact, nonlinear devices.
Collapse
|
43
|
Hijazi H, Zeghouane M, Dubrovskii VG. Thermodynamics of the Vapor-Liquid-Solid Growth of Ternary III-V Nanowires in the Presence of Silicon. NANOMATERIALS 2021; 11:nano11010083. [PMID: 33401772 PMCID: PMC7823983 DOI: 10.3390/nano11010083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 12/23/2020] [Accepted: 12/29/2020] [Indexed: 11/16/2022]
Abstract
Based on a thermodynamic model, we quantify the impact of adding silicon atoms to a catalyst droplet on the nucleation and growth of ternary III–V nanowires grown via the self-catalyzed vapor–liquid–solid process. Three technologically relevant ternaries are studied: InGaAs, AlGaAs and InGaN. For As-based alloys, it is shown that adding silicon atoms to the droplet increases the nanowire nucleation probability, which can increase by several orders magnitude depending on the initial chemical composition of the catalyst. Conversely, silicon atoms are found to suppress the nucleation rate of InGaN nanowires of different compositions. These results can be useful for understanding and controlling the vapor–liquid–solid growth of ternary III–V nanowires on silicon substrates as well as their intentional doping with Si.
Collapse
Affiliation(s)
- Hadi Hijazi
- Faculty of Laser Photonics and Optoelectronics, ITMO University, Kronverkskiy prospect 49, 197101 Saint Petersburg, Russia
- Correspondence:
| | - Mohammed Zeghouane
- CNRS, SIGMA Clermont, Institut Pascal, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France;
| | - Vladimir G. Dubrovskii
- Faculty of Physics, St. Petersburg State University, Universitetskaya Emb. 13B, 199034 St. Petersburg, Russia;
| |
Collapse
|
44
|
Liang D, E. Bowers J. Recent Progress in Heterogeneous III-V-on-Silicon Photonic Integration. ACTA ACUST UNITED AC 2021. [DOI: 10.37188/lam.2021.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
45
|
Marty G, Combrié S, Raineri F, De Rossi A. Photonic Crystal Optical Parametric Oscillator. NATURE PHOTONICS 2021; 15:53-58. [PMID: 33767738 PMCID: PMC7610394 DOI: 10.1038/s41566-020-00737-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
We report a new class of Optical Parametric Oscillators, based on a 20μm-long semiconductor Photonic Crystal Cavity and operating at Telecom wavelengths. Because the confinement results from Bragg scattering, the optical cavity contains a few modes, approximately equispaced in frequency. Parametric oscillation is reached when these high Q modes are thermally tuned into a triply resonant configuration, whereas any other parametric interaction is strongly suppressed. The lowest pump power threshold is estimated to 50 - 70μW. This source behaves as an ideal degenerate Optical Parametric Oscillator addressing the needs in the field of quantum optical circuits, paving the way to the dense integration of highly efficient nonlinear sources of squeezed light or entangled photons pairs.
Collapse
Affiliation(s)
- Gabriel Marty
- Thales Research and Technology, Campus Polytechnique, 1 avenue Augustin Fresnel, 91767 Palaiseau, France
- Centre de Nanosciences et de Nanotetchnologies, CNRS, Université Paris Saclay, Palaiseau, France
| | - Sylvain Combrié
- Thales Research and Technology, Campus Polytechnique, 1 avenue Augustin Fresnel, 91767 Palaiseau, France
| | - Fabrice Raineri
- Centre de Nanosciences et de Nanotetchnologies, CNRS, Université Paris Saclay, Palaiseau, France
- Université de Paris, 75006 Paris, France
| | - Alfredo De Rossi
- Thales Research and Technology, Campus Polytechnique, 1 avenue Augustin Fresnel, 91767 Palaiseau, France
| |
Collapse
|
46
|
Sun D, Zhang Y, Wang D, Song W, Liu X, Pang J, Geng D, Sang Y, Liu H. Microstructure and domain engineering of lithium niobate crystal films for integrated photonic applications. LIGHT, SCIENCE & APPLICATIONS 2020; 9:197. [PMID: 33303741 PMCID: PMC7729400 DOI: 10.1038/s41377-020-00434-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 11/08/2020] [Accepted: 11/12/2020] [Indexed: 05/20/2023]
Abstract
Recently, integrated photonics has attracted considerable interest owing to its wide application in optical communication and quantum technologies. Among the numerous photonic materials, lithium niobate film on insulator (LNOI) has become a promising photonic platform owing to its electro-optic and nonlinear optical properties along with ultralow-loss and high-confinement nanophotonic lithium niobate waveguides fabricated by the complementary metal-oxide-semiconductor (CMOS)-compatible microstructure engineering of LNOI. Furthermore, ferroelectric domain engineering in combination with nanophotonic waveguides on LNOI is gradually accelerating the development of integrated nonlinear photonics, which will play an important role in quantum technologies because of its ability to be integrated with the generation, processing, and auxiliary detection of the quantum states of light. Herein, we review the recent progress in CMOS-compatible microstructure engineering and domain engineering of LNOI for integrated lithium niobate photonics involving photonic modulation and nonlinear photonics. We believe that the great progress in integrated photonics on LNOI will lead to a new generation of techniques. Thus, there remains an urgent need for efficient methods for the preparation of LNOI that are suitable for large-scale and low-cost manufacturing of integrated photonic devices and systems.
Collapse
Affiliation(s)
- Dehui Sun
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Jinan, 250022, China.
| | - Yunwu Zhang
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Jinan, 250022, China
| | - Dongzhou Wang
- Jinan Institute of Quantum Technology, Jinan, 250101, China
| | - Wei Song
- CETC Deqing Huaying Electronics Co., Ltd., Huzhou, 313200, China
| | - Xiaoyan Liu
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Jinan, 250022, China
| | - Jinbo Pang
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Jinan, 250022, China
| | - Deqiang Geng
- Crystrong Photoelectric Technology Co., Ltd., Jinan, 250100, China
| | - Yuanhua Sang
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Hong Liu
- Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Jinan, 250022, China.
- Jinan Institute of Quantum Technology, Jinan, 250101, China.
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China.
| |
Collapse
|
47
|
Yao XS, Liu X, Hao P. Scan-less 3D optical sensing/Lidar scheme enabled by wavelength division demultiplexing and position-to-angle conversion of a lens. OPTICS EXPRESS 2020; 28:35884-35897. [PMID: 33379695 DOI: 10.1364/oe.409473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/01/2020] [Indexed: 06/12/2023]
Abstract
We propose a novel scheme for 3D sensing or Lidar without the need for beam scan or 2D photo-imaging. The scheme is enabled by the combination of a lens' position-to-angle conversion and the wavelength division multiplexing/demultiplexing (WDM) commonly used in optical fiber communication systems. However, unlike in a WDM system where different wavelengths carry different data channels, here lights of different wavelengths are demultiplexed into different waveguides or fibers with their exiting ends placed in the focal plane of the lens, which converts the exiting lights into beams of different angles to form a 1D or 2D beam array according to the relative position of the fiber ends with respect to the optical axis of the lens for illuminating the targets and finally sensing the light reflected from different directions. The returned signals are then demultiplexed into different photodetectors to determine the distances of the reflections in different directions. We show that the scheme has the potential to be implemented in photonics integrated circuit (PIC) for low cost production. We successfully demonstrate the scheme with the off-the-shelf discrete fiber optic components using 4 WDM channels and time-of-flight (ToF) technique for distance measurement, although hundreds wavelength channels from a photonic integrated microcomb may be used in practice. Finally, we demonstrate that the angular resolution of the beam array of different wavelengths can be improved by dithering the fiber array or the lens. We believe this new scheme provides an attractive alternative to the MEMS and optical phased array based beam scanning and can be explored further to enable low cost and high speed 3D sensing, particularly Lidar systems.
Collapse
|
48
|
Xie W, Chang L, Shu H, Norman JC, Peters JD, Wang X, Bowers JE. Ultrahigh-Q AlGaAs-on-insulator microresonators for integrated nonlinear photonics. OPTICS EXPRESS 2020; 28:32894-32906. [PMID: 33114964 DOI: 10.1364/oe.405343] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/06/2020] [Indexed: 06/11/2023]
Abstract
Aluminum gallium arsenide (AlGaAs) and related III-V semiconductors have excellent optoelectronic properties. They also possess strong material nonlinearity as well as high refractive indices. In view of these properties, AlGaAs is a promising candidate for integrated photonics, including both linear and nonlinear devices, passive and active devices, and associated applications. Low propagation loss is essential for integrated photonics, particularly in nonlinear applications. However, achieving low-loss and high-confinement AlGaAs photonic integrated circuits poses a challenge. Here we show an effective reduction of surface-roughness-induced scattering loss in fully etched high-confinement AlGaAs-on-insulator nanowaveguides by using a heterogeneous wafer-bonding approach and optimizing fabrication techniques. We demonstrate ultrahigh-quality AlGaAs microring resonators and realize quality factors up to 3.52 × 106 and finesses as high as 1.4 × 104. We also show ultra-efficient frequency comb generations in those resonators and achieve record-low threshold powers on the order of ∼20 µW and ∼120 µW for the resonators with 1 THz and 90 GHz free-spectral ranges, respectively. Our result paves the way for the implementation of AlGaAs as a novel integrated material platform specifically for nonlinear photonics and opens a new window for chip-based efficiency-demanding practical applications.
Collapse
|
49
|
Woods JRC, Daykin J, Tong ASK, Lacava C, Petropoulos P, Tropper AC, Horak P, Wilkinson JS, Apostolopoulos V. Supercontinuum generation in tantalum pentoxide waveguides for pump wavelengths in the 900 nm to 1500 nm spectral region. OPTICS EXPRESS 2020; 28:32173-32184. [PMID: 33115180 DOI: 10.1364/oe.403089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/11/2020] [Indexed: 06/11/2023]
Abstract
We characterize the spectral broadening performance in silica clad and unclad Tantalum pentoxide (Ta2O5) waveguides as a function of the input pulse central wavelength and polarization, sweeping over a wavelength range from 900 nm to 1500 nm, with an average incident power of 110 mW. The waveguides are 0.7 µm high and between 2.2 and 3.2 µm wide, and the SiO2 top cladding layer is 2 µm thick. We model the dispersion of the higher order spatial modes, and use numerical simulations based on the generalized nonlinear Schrödinger equation to analyze the nonlinear behaviour of the spatial modes within the waveguides as well as the dispersive effects observed in the experiments. We achieve octave spanning supercontinuum with an average power of 175 mW incident on the waveguide at 1000 nm pump wavelength.
Collapse
|
50
|
Wu L, Wang H, Yang Q, Ji QX, Shen B, Bao C, Gao M, Vahala K. Greater than one billion Q factor for on-chip microresonators. OPTICS LETTERS 2020; 45:5129-5131. [PMID: 32932469 DOI: 10.1364/ol.394940] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
High optical quality (Q) factors are critically important in optical microcavities, where performance in applications spanning nonlinear optics to cavity quantum electrodynamics is determined. Here, a record Q factor of over 1.1 billion is demonstrated for on-chip optical resonators. Using silica whispering-gallery resonators on silicon, Q-factor data is measured over wavelengths spanning the C/L bands (100 nm) and for a range of resonator sizes and mode families. A record low sub-milliwatt parametric oscillation threshold is also measured in 9 GHz free-spectral-range devices. The results show the potential for thermal silica on silicon as a resonator material.
Collapse
|