1
|
Barkey M, Büchner R, Wester A, Pritzl SD, Makarenko M, Wang Q, Weber T, Trauner D, Maier SA, Fratalocchi A, Lohmüller T, Tittl A. Pixelated High- Q Metasurfaces for in Situ Biospectroscopy and Artificial Intelligence-Enabled Classification of Lipid Membrane Photoswitching Dynamics. ACS Nano 2024. [PMID: 38653474 DOI: 10.1021/acsnano.3c09798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Nanophotonic devices excel at confining light into intense hot spots of electromagnetic near fields, creating exceptional opportunities for light-matter coupling and surface-enhanced sensing. Recently, all-dielectric metasurfaces with ultrasharp resonances enabled by photonic bound states in the continuum (BICs) have unlocked additional functionalities for surface-enhanced biospectroscopy by precisely targeting and reading out the molecular absorption signatures of diverse molecular systems. However, BIC-driven molecular spectroscopy has so far focused on end point measurements in dry conditions, neglecting the crucial interaction dynamics of biological systems. Here, we combine the advantages of pixelated all-dielectric metasurfaces with deep learning-enabled feature extraction and prediction to realize an integrated optofluidic platform for time-resolved in situ biospectroscopy. Our approach harnesses high-Q metasurfaces specifically designed for operation in a lossy aqueous environment together with advanced spectral sampling techniques to temporally resolve the dynamic behavior of photoswitchable lipid membranes. Enabled by a software convolutional neural network, we further demonstrate the real-time classification of the characteristic cis and trans membrane conformations with 98% accuracy. Our synergistic sensing platform incorporating metasurfaces, optofluidics, and deep learning reveals exciting possibilities for studying multimolecular biological systems, ranging from the behavior of transmembrane proteins to the dynamic processes associated with cellular communication.
Collapse
Affiliation(s)
- Martin Barkey
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-Universtität München, Königinstraße 10, 80539 München, Germany
| | - Rebecca Büchner
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-Universtität München, Königinstraße 10, 80539 München, Germany
- Nanophotonic Systems Laboratory, ETH Zürich, 8092 Zürich, Switzerland
| | - Alwin Wester
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-Universtität München, Königinstraße 10, 80539 München, Germany
| | - Stefanie D Pritzl
- Chair for Photonics and Optoelectronics, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-Universtität München, Königinstraße 10, 80539 München, Germany
- Department of Physics and Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands
| | - Maksim Makarenko
- PRIMALIGHT, Faculty of Electrical Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Qizhou Wang
- PRIMALIGHT, Faculty of Electrical Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Thomas Weber
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-Universtität München, Königinstraße 10, 80539 München, Germany
| | - Dirk Trauner
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Stefan A Maier
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-Universtität München, Königinstraße 10, 80539 München, Germany
- School of Physics and Astronomy, Monash University, Wellington Road, Clayton, VIC 3800, Australia
- The Blackett Laboratory, Department of Physics, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Andrea Fratalocchi
- PRIMALIGHT, Faculty of Electrical Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Theobald Lohmüller
- Chair for Photonics and Optoelectronics, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-Universtität München, Königinstraße 10, 80539 München, Germany
| | - Andreas Tittl
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-Universtität München, Königinstraße 10, 80539 München, Germany
| |
Collapse
|
2
|
Sortino L, Gale A, Kühner L, Li C, Biechteler J, Wendisch FJ, Kianinia M, Ren H, Toth M, Maier SA, Aharonovich I, Tittl A. Optically addressable spin defects coupled to bound states in the continuum metasurfaces. Nat Commun 2024; 15:2008. [PMID: 38443418 PMCID: PMC10914779 DOI: 10.1038/s41467-024-46272-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 02/16/2024] [Indexed: 03/07/2024] Open
Abstract
Van der Waals (vdW) materials, including hexagonal boron nitride (hBN), are layered crystalline solids with appealing properties for investigating light-matter interactions at the nanoscale. hBN has emerged as a versatile building block for nanophotonic structures, and the recent identification of native optically addressable spin defects has opened up exciting possibilities in quantum technologies. However, these defects exhibit relatively low quantum efficiencies and a broad emission spectrum, limiting potential applications. Optical metasurfaces present a novel approach to boost light emission efficiency, offering remarkable control over light-matter coupling at the sub-wavelength regime. Here, we propose and realise a monolithic scalable integration between intrinsic spin defects in hBN metasurfaces and high quality (Q) factor resonances, exceeding 102, leveraging quasi-bound states in the continuum (qBICs). Coupling between defect ensembles and qBIC resonances delivers a 25-fold increase in photoluminescence intensity, accompanied by spectral narrowing to below 4 nm linewidth and increased narrowband spin-readout efficiency. Our findings demonstrate a new class of metasurfaces for spin-defect-based technologies and pave the way towards vdW-based nanophotonic devices with enhanced efficiency and sensitivity for quantum applications in imaging, sensing, and light emission.
Collapse
Affiliation(s)
- Luca Sortino
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany
| | - Angus Gale
- School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Lucca Kühner
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany
| | - Chi Li
- School of Physics and Astronomy, Monash University, Wellington Rd, Clayton, VIC 3800, Australia
| | - Jonas Biechteler
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany
| | - Fedja J Wendisch
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany
| | - Mehran Kianinia
- School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Haoran Ren
- School of Physics and Astronomy, Monash University, Wellington Rd, Clayton, VIC 3800, Australia
| | - Milos Toth
- School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW, 2007, Australia
- ARC Centre of Excellence for Transformative Meta-Optical Systems, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Stefan A Maier
- School of Physics and Astronomy, Monash University, Wellington Rd, Clayton, VIC 3800, Australia
- The Blackett Laboratory, Department of Physics, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Igor Aharonovich
- School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
- ARC Centre of Excellence for Transformative Meta-Optical Systems, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
| | - Andreas Tittl
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany.
| |
Collapse
|
3
|
Duportal M, Berger LM, Maier SA, Tittl A, Krischer K. Multi-band Metasurface-Driven Surface-Enhanced Infrared Absorption Spectroscopy for Improved Characterization of in-Situ Electrochemical Reactions. ACS Photonics 2024; 11:714-722. [PMID: 38405393 PMCID: PMC10885203 DOI: 10.1021/acsphotonics.3c01592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/19/2023] [Accepted: 12/20/2023] [Indexed: 02/27/2024]
Abstract
Surface-enhanced spectroscopy techniques are the method-of-choice to characterize adsorbed intermediates occurring during electrochemical reactions, which are crucial in realizing a green and sustainable future. Characterizing species with low coverage or short lifetimes has so far been limited by low signal enhancement. Recently, single-band metasurface-driven surface-enhanced infrared absorption spectroscopy (SEIRAS) has been pioneered as a promising technology to monitor a single vibrational mode during electrochemical CO oxidation. However, electrochemical reactions are complex, and their understanding requires the simultaneous monitoring of multiple adsorbed species in situ, hampering the adoption of nanostructured electrodes in spectro-electrochemistry. Here, we develop a multi-band nanophotonic-electrochemical platform that simultaneously monitors in situ multiple adsorbed species emerging during cyclic voltammetry scans by leveraging the high resolution offered by the reproducible nanostructuring of the working electrode. Specifically, we studied the electrochemical reduction of CO2 on a Pt surface and used two separately tuned metasurface arrays to monitor two adsorption configurations of CO with vibrational bands at ∼2030 and ∼1840 cm-1. Our platform provides a ∼40-fold enhancement in the detection of characteristic absorption signals compared to conventional broadband electrochemically roughened platinum films. A straightforward methodology is outlined starting with baselining our system in a CO-saturated environment and clearly detecting both configurations of adsorption. In contrast, during the electrochemical reduction of CO2 on platinum in K2CO3, CO adsorbed in a bridged configuration could not be detected. We anticipate that our technology will guide researchers in developing similar sensing platforms to simultaneously detect multiple challenging intermediates, with low surface coverage or short lifetimes.
Collapse
Affiliation(s)
- Malo Duportal
- Department
of Physics, Technical University of Munich, Garching 85748, Germany
| | - Luca M. Berger
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience,
Faculty of Physics, Ludwig-Maximilians-University
Munich, Königinstraße
10, München 80539, Germany
| | - Stefan A. Maier
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience,
Faculty of Physics, Ludwig-Maximilians-University
Munich, Königinstraße
10, München 80539, Germany
- School
of Physics and Astronomy, Monash University, Clayton, VIC 3800, Australia
- Department
of Physics, Imperial College London, London SW7 2AZ, United Kingdom
| | - Andreas Tittl
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience,
Faculty of Physics, Ludwig-Maximilians-University
Munich, Königinstraße
10, München 80539, Germany
| | - Katharina Krischer
- Department
of Physics, Technical University of Munich, Garching 85748, Germany
| |
Collapse
|
4
|
Kühner L, Wendisch FJ, Antonov AA, Bürger J, Hüttenhofer L, de S Menezes L, Maier SA, Gorkunov MV, Kivshar Y, Tittl A. Unlocking the out-of-plane dimension for photonic bound states in the continuum to achieve maximum optical chirality. Light Sci Appl 2023; 12:250. [PMID: 37828041 PMCID: PMC10570380 DOI: 10.1038/s41377-023-01295-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 10/14/2023]
Abstract
The realization of lossless metasurfaces with true chirality crucially requires the fabrication of three-dimensional structures, constraining experimental feasibility and hampering practical implementations. Even though the three-dimensional assembly of metallic nanostructures has been demonstrated previously, the resulting plasmonic resonances suffer from high intrinsic and radiative losses. The concept of photonic bound states in the continuum (BICs) is instrumental for tailoring radiative losses in diverse geometries, especially when implemented using lossless dielectrics, but applications have so far been limited to planar structures. Here, we introduce a novel nanofabrication approach to unlock the height of individual resonators within all-dielectric metasurfaces as an accessible parameter for the efficient control of resonance features and nanophotonic functionalities. In particular, we realize out-of-plane symmetry breaking in quasi-BIC metasurfaces and leverage this design degree of freedom to demonstrate an optical all-dielectric quasi-BIC metasurface with maximum intrinsic chirality that responds selectively to light of a particular circular polarization depending on the structural handedness. Our experimental results not only open a new paradigm for all-dielectric BICs and chiral nanophotonics, but also promise advances in the realization of efficient generation of optical angular momentum, holographic metasurfaces, and parity-time symmetry-broken optical systems.
Collapse
Affiliation(s)
- Lucca Kühner
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, 80539, München, Germany
| | - Fedja J Wendisch
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, 80539, München, Germany
| | - Alexander A Antonov
- Shubnikov Institute of Crystallography, FSRC "Crystallography and Photonics", Russian Academy of Sciences, Moscow, 119333, Russia
| | - Johannes Bürger
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, 80539, München, Germany
| | - Ludwig Hüttenhofer
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, 80539, München, Germany
| | - Leonardo de S Menezes
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, 80539, München, Germany
- Departamento de Física, Universidade Federal de Pernambuco, 50670-901, Recife, Pernambuco, Brazil
| | - Stefan A Maier
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, 80539, München, Germany
- School of Physics and Astronomy, Monash University, Wellington Rd, Clayton, VIC, 3800, Australia
- The Blackett Laboratory, Department of Physics, Imperial College London, London, SW7 2AZ, UK
| | - Maxim V Gorkunov
- Shubnikov Institute of Crystallography, FSRC "Crystallography and Photonics", Russian Academy of Sciences, Moscow, 119333, Russia
| | - Yuri Kivshar
- Nonlinear Physics Centre, Research School of Physics, Australian National University, Canberra, ACT, 2601, Australia.
| | - Andreas Tittl
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, 80539, München, Germany.
| |
Collapse
|
5
|
Gryb D, Wendisch FJ, Aigner A, Gölz T, Tittl A, de S. Menezes L, Maier SA. Two-Dimensional Chiral Metasurfaces Obtained by Geometrically Simple Meta-atom Rotations. Nano Lett 2023; 23:8891-8897. [PMID: 37726256 PMCID: PMC10571149 DOI: 10.1021/acs.nanolett.3c02168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 08/21/2023] [Indexed: 09/21/2023]
Abstract
Two-dimensional chiral metasurfaces seem to contradict Lord Kelvin's geometric definition of chirality since they can be made to coincide by performing rotational operations. Nevertheless, most planar chiral metasurface designs often use complex meta-atom shapes to create flat versions of three-dimensional helices, although the visual appearance does not improve their chiroptical response but complicates their optimization and fabrication due to the resulting large parameter space. Here we present one of the geometrically simplest two-dimensional chiral metasurface platforms consisting of achiral dielectric rods arranged in a square lattice. Chirality is created by rotating the individual meta-atoms, making their arrangement chiral and leading to chiroptical responses that are stronger or comparable to more complex designs. We show that resonances depending on the arrangement are robust against geometric variations and behave similarly in experiments and simulations. Finally, we explain the origin of chirality and behavior of our platform by simple considerations of the geometric asymmetry and gap size.
Collapse
Affiliation(s)
- Dmytro Gryb
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Department of Physics, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
| | - Fedja J. Wendisch
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Department of Physics, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
| | - Andreas Aigner
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Department of Physics, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
| | - Thorsten Gölz
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Department of Physics, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
| | - Andreas Tittl
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Department of Physics, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
| | - Leonardo de S. Menezes
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Department of Physics, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
- Departamento
de Física, Universidade Federal de
Pernambuco, 50670-901 Recife, PE, Brazil
| | - Stefan A. Maier
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Department of Physics, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
- School
of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia
- Department
of Physics, Imperial College London, London SW7 2AZ, United Kingdom
| |
Collapse
|
6
|
Beddoe M, Gölz T, Barkey M, Bau E, Godejohann M, Maier SA, Keilmann F, Moldovan M, Prodan D, Ilie N, Tittl A. Probing the micro- and nanoscopic properties of dental materials using infrared spectroscopy: A proof-of-principle study. Acta Biomater 2023; 168:309-322. [PMID: 37479158 DOI: 10.1016/j.actbio.2023.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 07/12/2023] [Accepted: 07/14/2023] [Indexed: 07/23/2023]
Abstract
The preservation of oral health over a person's lifespan is a key factor for a high quality of life. Sustaining oral health requires high-end dental materials with a plethora of attributes such as durability, non-toxicity and ease of application. The combination of different requirements leads to increasing miniaturization and complexity of the material components such as the composite and adhesives, which makes the precise characterization of the material blend challenging. Here, we demonstrate how modern IR spectroscopy and imaging from the micro- to the nanoscale can provide insights on the chemical composition of the different material sections of a dental filling. We show how the recorded IR-images can be used for a fast and non-destructive porosity determination of the studied adhesive. Furthermore, the nanoscale study allows precise assessment of glass cluster structures and distribution within their characteristic organically modified ceramic (ORMOCER) matrix and an assessment of the interface between the composite and adhesive material. For the study we used a Fourier-Transform-IR (FTIR) microscope and a quantum cascade laser-based IR-microscope (QCL-IR) for the microscale analysis and a scattering-type scanning near-field optical microscopy (s-SNOM) for the nanoscale analysis. The paper ends with an in-depth discussion of the strengths and weaknesses of the different imaging methods to give the reader a clear picture for which scientific question the microscopes are best suited for. STATEMENT OF SIGNIFICANCE: Modern resin-based composites for dental restoration are complex multi-compound materials. In order to improve these high-end materials, it is important to investigate the molecular composition and morphology of the different parts. An emergent method to characterize these materials is infrared spectroscopic imaging, which combines the strength of infrared spectroscopy and an imaging approach known from optical microscopy. In this work, three state of the art methods are compared for investigating a dental filling including FTIR- and quantum cascade laser IR-imaging microscopy for the microscale and scattering-type scanning near-field optical microscopy for the nanoscale.
Collapse
Affiliation(s)
- Max Beddoe
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig Maximilians-University Munich, Munich 80539, Germany; Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University Jena, Jena 07745, Germany; Institute of Solid State Physics, Friedrich Schiller University Jena, Jena 07743, Germany
| | - Thorsten Gölz
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig Maximilians-University Munich, Munich 80539, Germany
| | - Martin Barkey
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig Maximilians-University Munich, Munich 80539, Germany
| | - Enrico Bau
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig Maximilians-University Munich, Munich 80539, Germany
| | | | - Stefan A Maier
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig Maximilians-University Munich, Munich 80539, Germany; School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia; Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom
| | - Fritz Keilmann
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig Maximilians-University Munich, Munich 80539, Germany
| | - Marioara Moldovan
- Babes-Bolyai University, Institute of Chemistry Raluca Ripan, Cluj-Napoca, Romania
| | - Doina Prodan
- Babes-Bolyai University, Institute of Chemistry Raluca Ripan, Cluj-Napoca, Romania
| | - Nicoleta Ilie
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Germany.
| | - Andreas Tittl
- Chair in Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig Maximilians-University Munich, Munich 80539, Germany.
| |
Collapse
|
7
|
Weber T, Kühner L, Sortino L, Ben Mhenni A, Wilson NP, Kühne J, Finley JJ, Maier SA, Tittl A. Intrinsic strong light-matter coupling with self-hybridized bound states in the continuum in van der Waals metasurfaces. Nat Mater 2023; 22:970-976. [PMID: 37349392 PMCID: PMC10390334 DOI: 10.1038/s41563-023-01580-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 05/17/2023] [Indexed: 06/24/2023]
Abstract
Photonic bound states in the continuum (BICs) provide a standout platform for strong light-matter coupling with transition metal dichalcogenides (TMDCs) but have so far mostly been implemented as traditional all-dielectric metasurfaces with adjacent TMDC layers, incurring limitations related to strain, mode overlap and material integration. Here, we demonstrate intrinsic strong coupling in BIC-driven metasurfaces composed of nanostructured bulk tungsten disulfide (WS2) and exhibiting resonances with sharp, tailored linewidths and selective enhancement of light-matter interactions. Tuning of the BIC resonances across the exciton resonance in bulk WS2 is achieved by varying the metasurface unit cells, enabling strong coupling with an anticrossing pattern and a Rabi splitting of 116 meV. Crucially, the coupling strength itself can be controlled and is shown to be independent of material-intrinsic losses. Our self-hybridized metasurface platform can readily incorporate other TMDCs or excitonic materials to deliver fundamental insights and practical device concepts for polaritonic applications.
Collapse
Affiliation(s)
- Thomas Weber
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Lucca Kühner
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Luca Sortino
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Amine Ben Mhenni
- Walter Schottky Institut, Department of Physics, School of Natural Sciences, Technische Universität München, Garching, Germany
| | - Nathan P Wilson
- Walter Schottky Institut, Department of Physics, School of Natural Sciences, Technische Universität München, Garching, Germany
| | - Julius Kühne
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Jonathan J Finley
- Walter Schottky Institut, Department of Physics, School of Natural Sciences, Technische Universität München, Garching, Germany
| | - Stefan A Maier
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
- School of Physics and Astronomy, Monash University, Clayton, Victoria, Australia
- Department of Physics, Imperial College London, London, UK
| | - Andreas Tittl
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany.
| |
Collapse
|
8
|
John-Herpin A, Tittl A, Kühner L, Richter F, Huang SH, Shvets G, Oh SH, Altug H. Metasurface-Enhanced Infrared Spectroscopy: An Abundance of Materials and Functionalities. Adv Mater 2023; 35:e2110163. [PMID: 35638248 DOI: 10.1002/adma.202110163] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 04/15/2022] [Indexed: 06/15/2023]
Abstract
Infrared spectroscopy provides unique information on the composition and dynamics of biochemical systems by resolving the characteristic absorption fingerprints of their constituent molecules. Based on this inherent chemical specificity and the capability for label-free, noninvasive, and real-time detection, infrared spectroscopy approaches have unlocked a plethora of breakthrough applications for fields ranging from environmental monitoring and defense to chemical analysis and medical diagnostics. Nanophotonics has played a crucial role for pushing the sensitivity limits of traditional far-field spectroscopy by using resonant nanostructures to focus the incident light into nanoscale hot-spots of the electromagnetic field, greatly enhancing light-matter interaction. Metasurfaces composed of regular arrangements of such resonators further increase the design space for tailoring this nanoscale light control both spectrally and spatially, which has established them as an invaluable toolkit for surface-enhanced spectroscopy. Starting from the fundamental concepts of metasurface-enhanced infrared spectroscopy, a broad palette of resonator geometries, materials, and arrangements for realizing highly sensitive metadevices is showcased, with a special focus on emerging systems such as phononic and 2D van der Waals materials, and integration with waveguides for lab-on-a-chip devices. Furthermore, advanced sensor functionalities of metasurface-based infrared spectroscopy, including multiresonance, tunability, dielectrophoresis, live cell sensing, and machine-learning-aided analysis are highlighted.
Collapse
Affiliation(s)
- Aurelian John-Herpin
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| | - Andreas Tittl
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany
| | - Lucca Kühner
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany
| | - Felix Richter
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| | - Steven H Huang
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
| | - Gennady Shvets
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
| | - Sang-Hyun Oh
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Hatice Altug
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| |
Collapse
|
9
|
Berté R, Weber T, de Souza Menezes L, Kühner L, Aigner A, Barkey M, Wendisch FJ, Kivshar Y, Tittl A, Maier SA. Permittivity-Asymmetric Quasi-Bound States in the Continuum. Nano Lett 2023; 23:2651-2658. [PMID: 36946720 DOI: 10.1021/acs.nanolett.2c05021] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Breaking the in-plane geometric symmetry of dielectric metasurfaces allows us to access a set of electromagnetic states termed symmetry-protected quasi-bound states in the continuum (qBICs). Here we demonstrate that qBICs can also be accessed by a symmetry breaking in the permittivity of the comprising materials. While the physical size of atoms imposes a limit on the lowest achievable geometrical asymmetry, weak permittivity modulations due to carrier doping, and electro-optical Pockels and Kerr effects, usually considered insignificant, open the possibility of infinitesimal permittivity asymmetries for on-demand, dynamically tunable resonances of extremely high quality factors. As a proof-of-principle, we probe the excitation of permittivity-asymmetric qBICs (ε-qBICs) using a prototype Si/TiO2 metasurface, in which the asymmetry in the unit cell is provided by the permittivity contrast of the materials. ε-qBICs are also numerically demonstrated in 1D gratings, where quality-factor enhancement and tailored interference phenomena of qBICs are shown via the interplay of geometrical and permittivity asymmetries.
Collapse
Affiliation(s)
- Rodrigo Berté
- Chair in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, München 80539, Germany
- Instituto de Física, Universidade Federal de Goiás, Goiânia, Goiás 74001-970, Brazil
| | - Thomas Weber
- Chair in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, München 80539, Germany
| | - Leonardo de Souza Menezes
- Chair in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, München 80539, Germany
- Departamento de Física, Universidade Federal de Pernambuco, Recife, Pernambuco 50670-901Brazil
| | - Lucca Kühner
- Chair in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, München 80539, Germany
| | - Andreas Aigner
- Chair in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, München 80539, Germany
| | - Martin Barkey
- Chair in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, München 80539, Germany
| | - Fedja Jan Wendisch
- Chair in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, München 80539, Germany
| | - Yuri Kivshar
- Nonlinear Physics Centre, Research School of Physics Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Andreas Tittl
- Chair in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, München 80539, Germany
| | - Stefan A Maier
- Chair in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstrasse 10, München 80539, Germany
- School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia
- The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom
| |
Collapse
|
10
|
Kühner L, Sortino L, Tilmann B, Weber T, Watanabe K, Taniguchi T, Maier SA, Tittl A. High-Q Nanophotonics over the Full Visible Spectrum Enabled by Hexagonal Boron Nitride Metasurfaces. Adv Mater 2023; 35:e2209688. [PMID: 36585851 DOI: 10.1002/adma.202209688] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/14/2022] [Indexed: 06/17/2023]
Abstract
All-dielectric optical metasurfaces with high quality (Q) factors have been hampered by the lack of simultaneously lossless and high-refractive-index materials over the full visible spectrum. In fact, the use of low-refractive-index materials is unavoidable for extending the spectral coverage due to the inverse correlation between the bandgap energy (and therefore the optical losses) and the refractive index (n). However, for Mie resonant photonics, smaller refractive indices are associated with reduced Q factors and low mode volume confinement. Here, symmetry-broken quasi bound states in the continuum (qBICs) are leveraged to efficiently suppress radiation losses from the low-index (n ≈ 2) van der Waals material hexagonal boron nitride (hBN), realizing metasurfaces with high-Q resonances over the complete visible spectrum. The rational use of low- and high-refractive-index materials as resonator components is analyzed and the insights are harnessed to experimentally demonstrate sharp qBIC resonances with Q factors above 300, spanning wavelengths between 400 and 1000 nm from a single hBN flake. Moreover, the enhanced electric near fields are utilized to demonstrate second-harmonic generation with enhancement factors above 102 . These results provide a theoretical and experimental framework for the implementation of low-refractive-index materials as photonic media for metaoptics.
Collapse
Affiliation(s)
- Lucca Kühner
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539, München, Germany
| | - Luca Sortino
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539, München, Germany
| | - Benjamin Tilmann
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539, München, Germany
| | - Thomas Weber
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539, München, Germany
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Stefan A Maier
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539, München, Germany
- School of Physics and Astronomy, Monash University, Wellington Rd, Clayton, VIC, 3800, Australia
- The Blackett Laboratory, Department of Physics, Imperial College London, London, SW7 2AZ, UK
| | - Andreas Tittl
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, and Center for NanoScience, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539, München, Germany
| |
Collapse
|
11
|
Aigner A, Tittl A, Wang J, Weber T, Kivshar Y, Maier SA, Ren H. Plasmonic bound states in the continuum to tailor light-matter coupling. Sci Adv 2022; 8:eadd4816. [PMID: 36490330 PMCID: PMC9733921 DOI: 10.1126/sciadv.add4816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 11/04/2022] [Indexed: 06/03/2023]
Abstract
Plasmon resonances play a pivotal role in enhancing light-matter interactions in nanophotonics, but their low-quality factors have hindered applications demanding high spectral selectivity. Here, we demonstrate the design and 3D laser nanoprinting of plasmonic nanofin metasurfaces, which support symmetry-protected bound states in the continuum up to the fourth order. By breaking the nanofins' out-of-plane symmetry in parameter space, we achieve high-quality factor (up to 180) modes under normal incidence. The out-of-plane symmetry breaking can be fine-tuned by the nanofins' triangle angle, opening a pathway to precisely control the ratio of radiative to intrinsic losses. This enables access to the under-, critical, and over-coupled regimes, which we exploit for pixelated molecular sensing. We observe a strong dependence of the sensing performance on the coupling regime, demonstrating the importance of judicious tailoring of light-matter interactions. Our demonstration provides a metasurface platform for enhanced light-matter interaction with a wide range of applications.
Collapse
Affiliation(s)
- Andreas Aigner
- Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Munich, 80539, Germany
| | - Andreas Tittl
- Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Munich, 80539, Germany
| | - Juan Wang
- Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Munich, 80539, Germany
| | - Thomas Weber
- Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Munich, 80539, Germany
| | - Yuri Kivshar
- Nonlinear Physics Center, Research School of Physics Australian National University, Canberra, ACT 2601, Australia
| | - Stefan A. Maier
- Hybrid Nanosystems, Nano-Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Munich, 80539, Germany
- School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia
- Department of Physics, Imperial College London, London SW7 2AZ, UK
| | - Haoran Ren
- School of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia
| |
Collapse
|
12
|
Abstract
Nanostructured surfaces with designed optical functionalities, such as metasurfaces, allow efficient harvesting of light at the nanoscale, enhancing light-matter interactions for a wide variety of material combinations. Exploiting light-driven matter excitations in these artificial materials opens up a new dimension in the conversion and management of energy at the nanoscale. In this review, we outline the impact, opportunities, applications, and challenges of optical metasurfaces in converting the energy of incoming photons into frequency-shifted photons, phonons, and energetic charge carriers. A myriad of opportunities await for the utilization of the converted energy. Here we cover the most pertinent aspects from a fundamental nanoscopic viewpoint all the way to applications.
Collapse
Affiliation(s)
- Emiliano Cortés
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539 Munich, Germany,
| | - Fedja J. Wendisch
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539 Munich, Germany
| | - Luca Sortino
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539 Munich, Germany
| | - Andrea Mancini
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539 Munich, Germany
| | - Simone Ezendam
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539 Munich, Germany
| | - Seryio Saris
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539 Munich, Germany
| | - Leonardo de S. Menezes
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539 Munich, Germany,Departamento
de Física, Universidade Federal de
Pernambuco, 50670-901 Recife, Pernambuco, Brazil
| | - Andreas Tittl
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539 Munich, Germany
| | - Haoran Ren
- MQ Photonics
Research Centre, Department of Physics and Astronomy, Macquarie University, Macquarie
Park, New South Wales 2109, Australia
| | - Stefan A. Maier
- Chair
in Hybrid Nanosystems, Nano Institute Munich, Faculty of Physics, Ludwig-Maximilians-University Munich, Königinstraße 10, 80539 Munich, Germany,School
of Physics and Astronomy, Monash University, Clayton, Victoria 3800, Australia,Department
of Phyiscs, Imperial College London, London SW7 2AZ, United Kingdom,
| |
Collapse
|
13
|
Hu H, Weber T, Bienek O, Wester A, Hüttenhofer L, Sharp ID, Maier SA, Tittl A, Cortés E. Catalytic Metasurfaces Empowered by Bound States in the Continuum. ACS Nano 2022; 16:13057-13068. [PMID: 35953078 PMCID: PMC9413421 DOI: 10.1021/acsnano.2c05680] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/26/2022] [Indexed: 05/28/2023]
Abstract
Photocatalytic platforms based on ultrathin reactive materials facilitate carrier transport and extraction but are typically restricted to a narrow set of materials and spectral operating ranges due to limited absorption and poor energy-tuning possibilities. Metasurfaces, a class of 2D artificial materials based on the electromagnetic design of nanophotonic resonators, allow optical absorption engineering for a wide range of materials. Moreover, tailored resonances in nanostructured materials enable strong absorption enhancement and thus carrier multiplication. Here, we develop an ultrathin catalytic metasurface platform that leverages the combination of loss-engineered substoichiometric titanium oxide (TiO2-x) and the emerging physical concept of optical bound states in the continuum (BICs) to boost photocatalytic activity and provide broad spectral tunability. We demonstrate that our platform reaches the condition of critical light coupling in a TiO2-x BIC metasurface, thus providing a general framework for maximizing light-matter interactions in diverse photocatalytic materials. This approach can avoid the long-standing drawbacks of many naturally occurring semiconductor-based ultrathin films applied in photocatalysis, such as poor spectral tunability and limited absorption manipulation. Our results are broadly applicable to fields beyond photocatalysis, including photovoltaics and photodetectors.
Collapse
Affiliation(s)
- Haiyang Hu
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Königinstraße 10, 80539 München, Germany
| | - Thomas Weber
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Königinstraße 10, 80539 München, Germany
| | - Oliver Bienek
- Walter
Schottky Institute and Physics Department, Technical University Munich, Am Coulombwall 4, 85748 Garching, Germany
| | - Alwin Wester
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Königinstraße 10, 80539 München, Germany
| | - Ludwig Hüttenhofer
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Königinstraße 10, 80539 München, Germany
| | - Ian D. Sharp
- Walter
Schottky Institute and Physics Department, Technical University Munich, Am Coulombwall 4, 85748 Garching, Germany
| | - Stefan A. Maier
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Königinstraße 10, 80539 München, Germany
- School
of Physics and Astronomy, Monash University
Clayton Campus, Melbourne, Victoria 3800, Australia
- The
Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom
| | - Andreas Tittl
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Königinstraße 10, 80539 München, Germany
| | - Emiliano Cortés
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Königinstraße 10, 80539 München, Germany
| |
Collapse
|
14
|
Tittl A. Tunable structural colors on display. Light Sci Appl 2022; 11:155. [PMID: 35614063 PMCID: PMC9133000 DOI: 10.1038/s41377-022-00847-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Structural coloration takes inspiration from the bright hues found in nature to control the reflection and transmission of light from artificially structured materials. Combining them with active electrical tuning heralds breakthrough applications in optical displays.
Collapse
Affiliation(s)
- Andreas Tittl
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Königinstraße 10, 80539, München, Germany.
| |
Collapse
|
15
|
Mohammadi E, Tittl A, Tsakmakidis KL, Raziman TV, Curto AG. Dual Nanoresonators for Ultrasensitive Chiral Detection. ACS Photonics 2021; 8:1754-1762. [PMID: 34164565 PMCID: PMC8213055 DOI: 10.1021/acsphotonics.1c00311] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Indexed: 05/19/2023]
Abstract
The discrimination of enantiomers is crucial in biochemistry. However, chiral sensing faces significant limitations due to inherently weak chiroptical signals. Nanophotonics is a promising solution to enhance sensitivity thanks to increased optical chirality maximized by strong electric and magnetic fields. Metallic and dielectric nanoparticles can separately provide electric and magnetic resonances. Here we propose their synergistic combination in hybrid metal-dielectric nanostructures to exploit their dual character for superchiral fields beyond the limits of single particles. For optimal optical chirality, in addition to maximization of the resonance strength, the resonances must spectrally coincide. Simultaneously, their electric and magnetic fields must be parallel and π/2 out of phase and spatially overlap. We demonstrate that the interplay between the strength of the resonances and these optimal conditions constrains the attainable optical chirality in resonant systems. Starting from a simple symmetric nanodimer, we derive closed-form expressions elucidating its fundamental limits of optical chirality. Building on the trade-offs of different classes of dimers, we then suggest an asymmetric dual dimer based on realistic materials. These dual nanoresonators provide strong and decoupled electric and magnetic resonances together with optimal conditions for chiral fields. Finally, we introduce more complex dual building blocks for a metasurface with a record 300-fold enhancement of local optical chirality in nanoscale gaps, enabling circular dichroism enhancement by a factor of 20. By combining analytical insight and practical designs, our results put forward hybrid resonators to increase chiral sensitivity, particularly for small molecular quantities.
Collapse
Affiliation(s)
- Ershad Mohammadi
- Department
of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Andreas Tittl
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
| | - Kosmas L. Tsakmakidis
- Section
of Condensed Matter Physics, Department of Physics, National and Kapodistrian University of Athens, Panepistimioupolis, GR-157 84 Athens, Greece
| | - T. V. Raziman
- Department
of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Alberto G. Curto
- Department
of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| |
Collapse
|
16
|
Tittl A, John-Herpin A, Leitis A, Arvelo ER, Altug H. Metasurface-Based Molecular Biosensing Aided by Artificial Intelligence. Angew Chem Int Ed Engl 2019; 58:14810-14822. [PMID: 31021045 DOI: 10.1002/anie.201901443] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Indexed: 12/20/2022]
Abstract
Molecular spectroscopy provides unique information on the internal structure of biological materials by detecting the characteristic vibrational signatures of their constituent chemical bonds at infrared frequencies. Nanophotonic antennas and metasurfaces have driven this concept towards few-molecule sensitivity by confining incident light into intense hot spots of the electromagnetic fields, providing strongly enhanced light-matter interaction. In this Minireview, recently developed molecular biosensing approaches based on the combination of dielectric metasurfaces and imaging detection are highlighted in comparison to traditional plasmonic geometries, and the unique potential of artificial intelligence techniques for nanophotonic sensor design and data analysis is emphasized. Because of their spectrometer-less operation principle, such imaging-based approaches hold great promise for miniaturized biosensors in practical point-of-care or field-deployable applications.
Collapse
Affiliation(s)
- Andreas Tittl
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| | - Aurelian John-Herpin
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| | - Aleksandrs Leitis
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| | - Eduardo R Arvelo
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| | - Hatice Altug
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland
| |
Collapse
|
17
|
Tittl A, John‐Herpin A, Leitis A, Arvelo ER, Altug H. Metaoberflächen‐basierte molekulare Biosensorik unterstützt von künstlicher Intelligenz. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201901443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Andreas Tittl
- Institute of Bioengineering École Polytechnique Fédérale de Lausanne (EPFL) Lausanne 1015 Schweiz
| | - Aurelian John‐Herpin
- Institute of Bioengineering École Polytechnique Fédérale de Lausanne (EPFL) Lausanne 1015 Schweiz
| | - Aleksandrs Leitis
- Institute of Bioengineering École Polytechnique Fédérale de Lausanne (EPFL) Lausanne 1015 Schweiz
| | - Eduardo R. Arvelo
- Institute of Bioengineering École Polytechnique Fédérale de Lausanne (EPFL) Lausanne 1015 Schweiz
| | - Hatice Altug
- Institute of Bioengineering École Polytechnique Fédérale de Lausanne (EPFL) Lausanne 1015 Schweiz
| |
Collapse
|
18
|
Leitis A, Tittl A, Liu M, Lee BH, Gu MB, Kivshar YS, Altug H. Angle-multiplexed all-dielectric metasurfaces for broadband molecular fingerprint retrieval. Sci Adv 2019; 5:eaaw2871. [PMID: 31123705 PMCID: PMC6527437 DOI: 10.1126/sciadv.aaw2871] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 04/02/2019] [Indexed: 05/23/2023]
Abstract
Infrared spectroscopy resolves the structure of molecules by detecting their characteristic vibrational fingerprints. Subwavelength light confinement and nanophotonic enhancement have extended the scope of this technique for monolayer studies. However, current approaches still require complex spectroscopic equipment or tunable light sources. Here, we introduce a novel metasurface-based method for detecting molecular absorption fingerprints over a broad spectrum, which combines the device-level simplicity of state-of-the-art angle-scanning refractometric sensors with the chemical specificity of infrared spectroscopy. Specifically, we develop germanium-based high-Q metasurfaces capable of delivering a multitude of spectrally selective and surface-sensitive resonances between 1100 and 1800 cm-1. We use this approach to detect distinct absorption signatures of different interacting analytes including proteins, aptamers, and polylysine. In combination with broadband incoherent illumination and detection, our method correlates the total reflectance signal at each incidence angle with the strength of the molecular absorption, enabling spectrometer-less operation in a compact angle-scanning configuration ideally suited for field-deployable applications.
Collapse
Affiliation(s)
- Aleksandrs Leitis
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Andreas Tittl
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| | - Mingkai Liu
- Nonlinear Physics Centre, Australian National University, Canberra, ACT 2601, Australia
| | - Bang Hyun Lee
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Man Bock Gu
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Yuri S. Kivshar
- Nonlinear Physics Centre, Australian National University, Canberra, ACT 2601, Australia
| | - Hatice Altug
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland
| |
Collapse
|
19
|
John-Herpin A, Tittl A, Altug H. Quantifying the Limits of Detection of Surface-Enhanced Infrared Spectroscopy with Grating Order-Coupled Nanogap Antennas. ACS Photonics 2018; 5:4117-4124. [PMID: 30828588 PMCID: PMC6390698 DOI: 10.1021/acsphotonics.8b00847] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Indexed: 05/08/2023]
Abstract
Infrared spectroscopy is widely used for biomolecular studies, but struggles when investigating minute quantities of analytes due to the mismatch between vibrational cross sections and IR wavelengths. It is therefore beneficial to enhance absorption signals by confining the infrared light to deeply subwavelength volumes comparable in size to the biomolecules of interest. This can be achieved with surface-enhanced infrared absorption spectroscopy, for which plasmonic nanorod antennas represent the predominant implementation. However, unifying design guidelines for such systems are still lacking. Here, we introduce an experimentally verified framework for designing antenna-based molecular IR spectroscopy sensors. Specifically, we find that in order to maximize the sensing performance, it is essential to combine the signal enhancement originating from nanoscale gaps between the antenna elements with the enhancement obtained from coupling to the grating order modes of the unit cell. Using an optimized grating order-coupled nanogap design, our experiments and numerical simulations show a hotspot limit of detection of two proteins per nanogap. Furthermore, we introduce and analyze additional limit of detection parameters, specifically for deposited surface mass, in-solution concentration, and secondary structure determination. These limits of detection provide valuable reference points for performance metrics of surface-enhanced infrared absorption spectroscopy in practical applications, such as the characterization of biological samples in aqueous solution.
Collapse
|
20
|
Tittl A, Leitis A, Liu M, Yesilkoy F, Choi DY, Neshev DN, Kivshar YS, Altug H. Imaging-based molecular barcoding with pixelated dielectric metasurfaces. Science 2018; 360:1105-1109. [DOI: 10.1126/science.aas9768] [Citation(s) in RCA: 440] [Impact Index Per Article: 73.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/13/2018] [Indexed: 12/22/2022]
Abstract
Metasurfaces provide opportunities for wavefront control, flat optics, and subwavelength light focusing. We developed an imaging-based nanophotonic method for detecting mid-infrared molecular fingerprints and implemented it for the chemical identification and compositional analysis of surface-bound analytes. Our technique features a two-dimensional pixelated dielectric metasurface with a range of ultrasharp resonances, each tuned to a discrete frequency; this enables molecular absorption signatures to be read out at multiple spectral points, and the resulting information is then translated into a barcode-like spatial absorption map for imaging. The signatures of biological, polymer, and pesticide molecules can be detected with high sensitivity, covering applications such as biosensing and environmental monitoring. Our chemically specific technique can resolve absorption fingerprints without the need for spectrometry, frequency scanning, or moving mechanical parts, thereby paving the way toward sensitive and versatile miniaturized mid-infrared spectroscopy devices.
Collapse
|
21
|
Rodrigo D, Tittl A, Ait-Bouziad N, John-Herpin A, Limaj O, Kelly C, Yoo D, Wittenberg NJ, Oh SH, Lashuel HA, Altug H. Resolving molecule-specific information in dynamic lipid membrane processes with multi-resonant infrared metasurfaces. Nat Commun 2018; 9:2160. [PMID: 29867181 PMCID: PMC5986821 DOI: 10.1038/s41467-018-04594-x] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/04/2018] [Indexed: 12/12/2022] Open
Abstract
A multitude of biological processes are enabled by complex interactions between lipid membranes and proteins. To understand such dynamic processes, it is crucial to differentiate the constituent biomolecular species and track their individual time evolution without invasive labels. Here, we present a label-free mid-infrared biosensor capable of distinguishing multiple analytes in heterogeneous biological samples with high sensitivity. Our technology leverages a multi-resonant metasurface to simultaneously enhance the different vibrational fingerprints of multiple biomolecules. By providing up to 1000-fold near-field intensity enhancement over both amide and methylene bands, our sensor resolves the interactions of lipid membranes with different polypeptides in real time. Significantly, we demonstrate that our label-free chemically specific sensor can analyze peptide-induced neurotransmitter cargo release from synaptic vesicle mimics. Our sensor opens up exciting possibilities for gaining new insights into biological processes such as signaling or transport in basic research as well as provides a valuable toolkit for bioanalytical and pharmaceutical applications.
Collapse
Affiliation(s)
- Daniel Rodrigo
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860, Castelldefels, Spain
| | - Andreas Tittl
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Nadine Ait-Bouziad
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Aurelian John-Herpin
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Odeta Limaj
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Christopher Kelly
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
- School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, G12 8QQ, UK
| | - Daehan Yoo
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Nathan J Wittenberg
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
- Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Sang-Hyun Oh
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Hatice Altug
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
| |
Collapse
|
22
|
Rodrigo D, Tittl A, Limaj O, Abajo FJGD, Pruneri V, Altug H. Double-layer graphene for enhanced tunable infrared plasmonics. Light Sci Appl 2017; 6:e16277. [PMID: 30167262 PMCID: PMC6062234 DOI: 10.1038/lsa.2016.277] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 01/03/2017] [Accepted: 01/05/2017] [Indexed: 05/21/2023]
Abstract
Graphene is emerging as a promising material for photonic applications owing to its unique optoelectronic properties. Graphene supports tunable, long-lived and extremely confined plasmons that have great potential for applications such as biosensing and optical communications. However, in order to excite plasmonic resonances in graphene, this material requires a high doping level, which is challenging to achieve without degrading carrier mobility and stability. Here, we demonstrate that the infrared plasmonic response of a graphene multilayer stack is analogous to that of a highly doped single layer of graphene, preserving mobility and supporting plasmonic resonances with higher oscillator strength than previously explored single-layer devices. Particularly, we find that the optically equivalent carrier density in multilayer graphene is larger than the sum of those in the individual layers. Furthermore, electrostatic biasing in multilayer graphene is enhanced with respect to single layer due to the redistribution of carriers over different layers, thus extending the spectral tuning range of the plasmonic structure. The superior effective doping and improved tunability of multilayer graphene stacks should enable a plethora of future infrared plasmonic devices with high optical performance and wide tunability.
Collapse
Affiliation(s)
- Daniel Rodrigo
- Institute of BioEngineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Andreas Tittl
- Institute of BioEngineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Odeta Limaj
- Institute of BioEngineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - F Javier García de Abajo
- ICFO—Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- ICREA—Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
| | - Valerio Pruneri
- ICFO—Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- ICREA—Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
| | - Hatice Altug
- Institute of BioEngineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| |
Collapse
|
23
|
Bagheri S, Strohfeldt N, Sterl F, Berrier A, Tittl A, Giessen H. Large-Area Low-Cost Plasmonic Perfect Absorber Chemical Sensor Fabricated by Laser Interference Lithography. ACS Sens 2016. [DOI: 10.1021/acssensors.6b00444] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | - Andreas Tittl
- Institute
of BioEngineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | | |
Collapse
|
24
|
Sterl F, Strohfeldt N, Walter R, Griessen R, Tittl A, Giessen H. Magnesium as Novel Material for Active Plasmonics in the Visible Wavelength Range. Nano Lett 2015; 15:7949-55. [PMID: 26312401 DOI: 10.1021/acs.nanolett.5b03029] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Investigating new materials plays an important role for advancing the field of nanoplasmonics. In this work, we fabricate nanodisks from magnesium and demonstrate tuning of their plasmon resonance throughout the whole visible wavelength range by changing the disk diameter. Furthermore, we employ a catalytic palladium cap layer to transform the metallic Mg particles into dielectric MgH2 particles when exposed to hydrogen gas. We prove that this transition can be reversed in the presence of oxygen. This yields plasmonic nanostructures with an extinction spectrum that can be repeatedly switched on or off or kept at any intermediate state, offering new perspectives for active plasmonic metamaterials.
Collapse
Affiliation(s)
- Florian Sterl
- Fourth Physics Institute and Research Center SCoPE, University of Stuttgart , Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Nikolai Strohfeldt
- Fourth Physics Institute and Research Center SCoPE, University of Stuttgart , Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Ramon Walter
- Fourth Physics Institute and Research Center SCoPE, University of Stuttgart , Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Ronald Griessen
- Faculty of Sciences, Division of Physics and Astronomy, VU University , De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Andreas Tittl
- Fourth Physics Institute and Research Center SCoPE, University of Stuttgart , Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Harald Giessen
- Fourth Physics Institute and Research Center SCoPE, University of Stuttgart , Pfaffenwaldring 57, 70550 Stuttgart, Germany
| |
Collapse
|
25
|
Tittl A, Michel AKU, Schäferling M, Yin X, Gholipour B, Cui L, Wuttig M, Taubner T, Neubrech F, Giessen H. A Switchable Mid-Infrared Plasmonic Perfect Absorber with Multispectral Thermal Imaging Capability. Adv Mater 2015; 27:4597-603. [PMID: 26173394 DOI: 10.1002/adma.201502023] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Indexed: 05/14/2023]
Abstract
A switchable perfect absorber with multispectral thermal imaging capability is presented. Aluminum nanoantenna arrays above a germanium antimony telluride (GST) spacer layer and aluminum mirror provide efficient wavelength-tunable absorption in the mid-infrared. Utilizing the amorphous-to-crystalline phase transition in GST, this device offers switchable absorption with strong reflectance contrast at resonance and large phase-change-induced spectral shifts.
Collapse
Affiliation(s)
- Andreas Tittl
- 4th Physics Institute and Research Center Scope, University of Stuttgart, D-70569, Stuttgart, Germany
| | - Ann-Katrin U Michel
- I. Institute of Physics (IA), RWTH Aachen University, D-52056, Aachen, Germany
| | - Martin Schäferling
- 4th Physics Institute and Research Center Scope, University of Stuttgart, D-70569, Stuttgart, Germany
| | - Xinghui Yin
- 4th Physics Institute and Research Center Scope, University of Stuttgart, D-70569, Stuttgart, Germany
| | - Behrad Gholipour
- Centre for Disruptive Photonic Technologies, Nanyang Technological University, 637371, Singapore, Singapore
| | - Long Cui
- Centre for Disruptive Photonic Technologies, Nanyang Technological University, 637371, Singapore, Singapore
| | - Matthias Wuttig
- I. Institute of Physics (IA), RWTH Aachen University, D-52056, Aachen, Germany
| | - Thomas Taubner
- I. Institute of Physics (IA), RWTH Aachen University, D-52056, Aachen, Germany
| | - Frank Neubrech
- 4th Physics Institute and Research Center Scope, University of Stuttgart, D-70569, Stuttgart, Germany
| | - Harald Giessen
- 4th Physics Institute and Research Center Scope, University of Stuttgart, D-70569, Stuttgart, Germany
- Centre for Disruptive Photonic Technologies, Nanyang Technological University, 637371, Singapore, Singapore
| |
Collapse
|
26
|
Abstract
Active control over the handedness of a chiral metamaterial has the potential to serve as key element for highly integrated polarization engineering approaches, polarization sensitive imaging devices, and stereo display technologies. However, this is hard to achieve as it seemingly involves the reconfiguration of the metamolecule from a left-handed into a right-handed enantiomer and vice versa. This type of mechanical actuation is intricate and usually neither monolithically realizable nor viable for high-speed applications. Here, enabled by the phase change material Ge3Sb2Te6 (GST-326), we demonstrate a tunable and switchable mid-infrared plasmonic chiral metamaterial in a proof-of-concept experiment. A large tunability range of the circular dichroism response from λ = 4.15 to 4.90 μm is achieved, and we experimentally demonstrate that the combination of a passive bias-type chiral layer with the active chiral metamaterial allows for switchable chirality, that is, the reversal of the circular dichroism sign, in a fully planar, layered design without the need for geometrical reconfiguration. Because phase change materials can be electrically and optically switched, our designs may open up a path for highly integrated mid-IR polarization engineering devices that can be modulated on ultrafast time scales.
Collapse
Affiliation(s)
- Xinghui Yin
- †4th Physics Institute and Research Center SCoPE, University of Stuttgart, 70550, Stuttgart, Germany
- §Max Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - Martin Schäferling
- †4th Physics Institute and Research Center SCoPE, University of Stuttgart, 70550, Stuttgart, Germany
| | - Ann-Katrin U Michel
- ‡I. Institute of Physics (IA), RWTH Aachen University, 52056, Aachen, Germany
| | - Andreas Tittl
- †4th Physics Institute and Research Center SCoPE, University of Stuttgart, 70550, Stuttgart, Germany
| | - Matthias Wuttig
- ‡I. Institute of Physics (IA), RWTH Aachen University, 52056, Aachen, Germany
| | - Thomas Taubner
- ‡I. Institute of Physics (IA), RWTH Aachen University, 52056, Aachen, Germany
| | - Harald Giessen
- †4th Physics Institute and Research Center SCoPE, University of Stuttgart, 70550, Stuttgart, Germany
| |
Collapse
|
27
|
Tittl A, Harats MG, Walter R, Yin X, Schäferling M, Liu N, Rapaport R, Giessen H. Quantitative angle-resolved small-spot reflectance measurements on plasmonic perfect absorbers: impedance matching and disorder effects. ACS Nano 2014; 8:10885-10892. [PMID: 25251075 DOI: 10.1021/nn504708t] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Plasmonic devices with absorbance close to unity have emerged as essential building blocks for a multitude of technological applications ranging from trace gas detection to infrared imaging. A crucial requirement for such elements is the angle independence of the absorptive performance. In this work, we develop theoretically and verify experimentally a quantitative model for the angular behavior of plasmonic perfect absorber structures based on an optical impedance matching picture. To achieve this, we utilize a simple and elegant k-space measurement technique to record quantitative angle-resolved reflectance measurements on various perfect absorber structures. Particularly, this method allows quantitative reflectance measurements on samples where only small areas have been nanostructured, for example, by electron-beam lithography. Combining these results with extensive numerical modeling, we find that matching of both the real and imaginary parts of the optical impedance is crucial to obtain perfect absorption over a large angular range. Furthermore, we successfully apply our model to the angular dispersion of perfect absorber geometries with disordered plasmonic elements as a favorable alternative to current array-based designs.
Collapse
Affiliation(s)
- Andreas Tittl
- 4th Physics Institute and Research Center SCOPE, University of Stuttgart , D-70569 Stuttgart, Germany
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Strohfeldt N, Tittl A, Schäferling M, Neubrech F, Kreibig U, Griessen R, Giessen H. Yttrium hydride nanoantennas for active plasmonics. Nano Lett 2014; 14:1140-7. [PMID: 24576073 DOI: 10.1021/nl403643v] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
A key challenge for the development of active plasmonic nanodevices is the lack of materials with fully controllable plasmonic properties. In this work, we demonstrate that a plasmonic resonance in top-down nanofabricated yttrium antennas can be completely and reversibly turned on and off using hydrogen exposure. We fabricate arrays of yttrium nanorods and optically observe, in extinction spectra, the hydrogen-induced phase transition between the metallic yttrium dihydride and the insulating trihydride. Whereas the yttrium dihydride nanostructures exhibit a pronounced particle plasmon resonance, the transition to yttrium trihydride leads to a complete vanishing of the resonant behavior. The plasmonic resonance in the dihydride state can be tuned over a wide wavelength range by simply varying the size of the nanostructures. Furthermore, we develop an analytical diffusion model to explain the temporal behavior of the hydrogen loading and unloading trajectories observed in our experiments and gain information about the thermodynamics of our device. Thus, our nanorod system serves as a versatile basic building block for active plasmonic devices ranging from switchable perfect absorbers to active local heating control elements.
Collapse
Affiliation(s)
- Nikolai Strohfeldt
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart , Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | | | | | | | | | | | | |
Collapse
|
29
|
Tittl A, Yin X, Giessen H, Tian XD, Tian ZQ, Kremers C, Chigrin DN, Liu N. Plasmonic smart dust for probing local chemical reactions. Nano Lett 2013; 13:1816-21. [PMID: 23458121 DOI: 10.1021/nl4005089] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Locally probing chemical reactions or catalytic processes on surfaces under realistic reaction conditions has remained one of the main challenges in materials science and heterogeneous catalysis. Where conventional surface interrogation techniques usually require high-vacuum conditions or ensemble average measurements, plasmonic nanoparticles excel in extreme light focusing and can produce highly confined electromagnetic fields in subwavelength volumes without the need for complex near-field microscopes. Here, we demonstrate an all-optical probing technique based on plasmonic smart dust for monitoring local chemical reactions in real time. The silica shell-isolated gold nanoparticles that form the smart dust can work as strong light concentrators and optically report subtle environmental changes at their pinning sites on the probed surface during reaction processes. As a model system, we investigate the hydrogen dissociation and subsequent uptake trajectory in palladium with both "dust-on-film" and "film-on-dust" platforms. Using time-resolved single particle measurements, we demonstrate that our technique can in situ encode chemical reaction information as optical signals for a variety of surface morphologies. The presented technique offers a unique scheme for real-time, label-free, and high-resolution probing of local reaction kinetics in a plethora of important chemical reactions on surfaces, paving the way toward the development of inexpensive and high-output reaction sensors for real-world applications.
Collapse
Affiliation(s)
- Andreas Tittl
- 4h Physics Institute and Research Center Scope, University of Stuttgart, Stuttgart, Germany
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Tittl A, Mai P, Taubert R, Dregely D, Liu N, Giessen H. Palladium-based plasmonic perfect absorber in the visible wavelength range and its application to hydrogen sensing. Nano Lett 2011; 11:4366-9. [PMID: 21877697 DOI: 10.1021/nl202489g] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report on the experimental realization of a palladium-based plasmonic perfect absorber at visible wavelengths and its application to hydrogen sensing. Our design exhibits a reflectance <0.5% and zero transmittance at 650 nm and the operation wavelength of the absorber can be tuned by varying its structural parameters. Exposure to hydrogen gas causes a rapid and reversible increase in reflectance on a time scale of seconds. This pronounced response introduces a novel optical hydrogen detection scheme with very high values of the relative intensity response.
Collapse
Affiliation(s)
- Andreas Tittl
- 4th Physics Institute and Research Center SCOPE, University of Stuttgart , D-70569 Stuttgart, Germany
| | | | | | | | | | | |
Collapse
|