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Hajian H, Zhang X, McCormack O, Zhang Y, Dobie J, Rukhlenko ID, Ozbay E, Louise Bradley A. Quasi-bound states in the continuum for electromagnetic induced transparency and strong excitonic coupling. OPTICS EXPRESS 2024; 32:19163-19174. [PMID: 38859057 DOI: 10.1364/oe.525535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 05/01/2024] [Indexed: 06/12/2024]
Abstract
Advancing on previous reports, we utilize quasi-bound states in the continuum (q-BICs) supported by a metasurface of TiO2 meta-atoms with broken inversion symmetry on an SiO2 substrate, for two possible applications. Firstly, we demonstrate that by tuning the metasurface's asymmetric parameter, a spectral overlap between a broad q-BIC and a narrow magnetic dipole resonance is achieved, yielding an electromagnetic induced transparency analogue with a 50 μs group delay. Secondly, we have found that, due to the strong coupling between the q-BIC and WS2 exciton at room temperature and normal incidence, by integrating a single layer of WS2 to the metasurface, a 37.9 meV Rabi splitting in the absorptance spectrum with 50% absorption efficiency is obtained. These findings promise feasible two-port devices for visible range slow-light characteristics or nanoscale excitonic coupling.
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Fang J, Yao K, Wang M, Yu Z, Zhang T, Jiang T, Huang S, Korgel BA, Terrones M, Alù A, Zheng Y. Observation of Room-Temperature Exciton-Polariton Emission from Wide-Ranging 2D Semiconductors Coupled with a Broadband Mie Resonator. NANO LETTERS 2023; 23:9803-9810. [PMID: 37879099 DOI: 10.1021/acs.nanolett.3c02540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
Two-dimensional exciton-polaritons in monolayer transition metal dichalcogenides (TMDs) exhibit practical advantages in valley coherence, optical nonlinearities, and even bosonic condensation owing to their light-emission capability. To achieve robust exciton-polariton emission, strong photon-exciton couplings are required at the TMD monolayer, which is challenging due to its atomic thickness. High-quality (Q) factor optical cavities with narrowband resonances are an effective approach but typically limited to a specific excitonic state of a certain TMD material. Herein, we achieve on-demand exciton-polariton emission from a wide range of TMDs at room temperature by hybridizing excitons with broadband Mie resonances spanning the whole visible spectrum. By confining broadband light at the TMD monolayer, our one type of Mie resonator on different TMDs enables enhanced light-matter interactions with multiple excitonic states simultaneously. We demonstrate multi-Rabi splittings and robust polaritonic photoluminescence in monolayer WSe2, WS2, and MoS2. The hybrid system also shows the potential to approach the ultrastrong coupling regime.
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Affiliation(s)
- Jie Fang
- Walker Department of Mechanical Engineering and Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Kan Yao
- Walker Department of Mechanical Engineering and Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Mingsong Wang
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
| | - Zhuohang Yu
- Department of Materials Science and Engineering, Department of Physics, Department of Chemistry, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Tianyi Zhang
- Department of Materials Science and Engineering, Department of Physics, Department of Chemistry, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Taizhi Jiang
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Suichu Huang
- Walker Department of Mechanical Engineering and Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Brian A Korgel
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Mauricio Terrones
- Department of Materials Science and Engineering, Department of Physics, Department of Chemistry, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Andrea Alù
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
- Physics Program, Graduate Center, City University of New York, New York, New York 10016, United States
| | - Yuebing Zheng
- Walker Department of Mechanical Engineering and Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
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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. NATURE MATERIALS 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] [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.
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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.
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Li M, Gao M, Zhang Q, Yang Y. Valley-dependent vortex emission from exciton-polariton in non-centrosymmetric transition metal dichalcogenide metasurfaces. OPTICS EXPRESS 2023; 31:19622-19631. [PMID: 37381373 DOI: 10.1364/oe.490067] [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
Transition metal dichalcogenides (TMDs) have attracted great attention in valleytronics. Owing to the giant valley coherence at room temperature, valley pseudospin of TMDs open a new degree of freedom to encode and process binary information. The valley pseudospin only exists in non-centrosymmetric TMDs (e.g., monolayer or 3R-stacked multilayer), which is prohibited in conventional centrosymmetric 2H-stacked crystals. Here, we propose a general recipe to generate valley-dependent vortex beams by using a mix-dimensional TMD metasurface composed of nanostructured 2H-stacked TMD crystals and monolayer TMDs. Such an ultrathin TMD metasurface involves a momentum-space polarization vortex around bound states in the continuum (BICs), which can simultaneously achieve strong coupling (i.e., form exciton polaritons) and valley-locked vortex emission. Moreover, we report that a full 3R-stacked TMD metasurface can also reveal the strong-coupling regime with an anti-crossing pattern and a Rabi splitting of 95 meV. The Rabi splitting can be precisely controlled by geometrically shaping the TMD metasurface. Our results provide an ultra-compact TMD platform for controlling and structuring valley exciton polariton, in which the valley information is linked with the topological charge of vortex emission, which may advance valleytronic, polaritonic, and optoelectronic applications.
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You S, Zhang Y, Fan M, Luo S, Zhou C. Strong light-matter interactions of exciton in bulk WS 2 and a toroidal dipole resonance. OPTICS LETTERS 2023; 48:1530-1533. [PMID: 36946970 DOI: 10.1364/ol.481063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
Exciton-polaritonic states are generated by strong interactions between photons and excitons in nanocavities. Bulk transition metal dichalcogenides (TMDCs) host excitons with a large binding energy at room temperature, and thus are regarded as an ideal platform for realizing exciton-polaritons. In this work, we investigate the strong coupling properties between high-Q toroidal dipole (TD) resonance and bulk WS2 excitons in a hybrid metasurface, consisting of Si3N4 nanodisk arrays with embedded WS2. Multipole decomposition and near-field distribution confirm that Si3N4 nanodisk arrays support strong TD resonance. The TD resonance wavelength is easily tuned to overlap with the bulk WS2 exciton wavelength, and strong coupling is observed when the bulk WS2 is integrated with the hollow nanodisk and the oscillator strength of the WS2 material is adjusted to be greater than 0.6. The Rabi splitting of the hybrid device is up to 65 meV. In addition, strong coupling is confirmed by the anticrossing of fluorescence enhancement in the hybrid Si3N4-WS2 metastructure. Our findings are expected to be of importance for both fundamental research in TMDC-based light-matter interactions and practical applications in the design of high-performance exciton-polariton devices.
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Strong Coupling between a Single Quantum Emitter and a Plasmonic Nanoantenna on a Metallic Film. NANOMATERIALS 2022; 12:nano12091440. [PMID: 35564149 PMCID: PMC9104281 DOI: 10.3390/nano12091440] [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: 03/03/2022] [Revised: 04/16/2022] [Accepted: 04/21/2022] [Indexed: 12/04/2022]
Abstract
The strong coupling between single quantum emitters and resonant optical micro/nanocavities is beneficial for understanding light and matter interactions. Here, we propose a plasmonic nanoantenna placed on a metal film to achieve an ultra-high electric field enhancement in the nanogap and an ultra-small optical mode volume. The strong coupling between a single quantum dot (QD) and the designed structure is investigated in detail by both numerical simulations and theoretical calculations. When a single QD is inserted into the nanogap of the silver nanoantenna, the scattering spectra show a remarkably large splitting and anticrossing behavior of the vacuum Rabi splitting, which can be achieved in the scattering spectra by optimizing the nanoantenna thickness. Our work shows another way to enhance the light/matter interaction at a single quantum emitter limit, which can be useful for many nanophotonic and quantum applications.
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Huang L, Krasnok A, Alú A, Yu Y, Neshev D, Miroshnichenko AE. Enhanced light-matter interaction in two-dimensional transition metal dichalcogenides. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:046401. [PMID: 34939940 DOI: 10.1088/1361-6633/ac45f9] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 12/16/2021] [Indexed: 05/27/2023]
Abstract
Two-dimensional (2D) transition metal dichalcogenide (TMDC) materials, such as MoS2, WS2, MoSe2, and WSe2, have received extensive attention in the past decade due to their extraordinary electronic, optical and thermal properties. They evolve from indirect bandgap semiconductors to direct bandgap semiconductors while their layer number is reduced from a few layers to a monolayer limit. Consequently, there is strong photoluminescence in a monolayer (1L) TMDC due to the large quantum yield. Moreover, such monolayer semiconductors have two other exciting properties: large binding energy of excitons and valley polarization. These properties make them become ideal materials for various electronic, photonic and optoelectronic devices. However, their performance is limited by the relatively weak light-matter interactions due to their atomically thin form factor. Resonant nanophotonic structures provide a viable way to address this issue and enhance light-matter interactions in 2D TMDCs. Here, we provide an overview of this research area, showcasing relevant applications, including exotic light emission, absorption and scattering features. We start by overviewing the concept of excitons in 1L-TMDC and the fundamental theory of cavity-enhanced emission, followed by a discussion on the recent progress of enhanced light emission, strong coupling and valleytronics. The atomically thin nature of 1L-TMDC enables a broad range of ways to tune its electric and optical properties. Thus, we continue by reviewing advances in TMDC-based tunable photonic devices. Next, we survey the recent progress in enhanced light absorption over narrow and broad bandwidths using 1L or few-layer TMDCs, and their applications for photovoltaics and photodetectors. We also review recent efforts of engineering light scattering, e.g., inducing Fano resonances, wavefront engineering in 1L or few-layer TMDCs by either integrating resonant structures, such as plasmonic/Mie resonant metasurfaces, or directly patterning monolayer/few layers TMDCs. We then overview the intriguing physical properties of different van der Waals heterostructures, and their applications in optoelectronic and photonic devices. Finally, we draw our opinion on potential opportunities and challenges in this rapidly developing field of research.
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Affiliation(s)
- Lujun Huang
- School of Engineering and Information Technology, University of New South Wales, Canberra, ACT, 2600, Australia
| | - Alex Krasnok
- Department of Electrical and Computer Engineering, Florida International University, Miami, FL 33174, United States of America
| | - Andrea Alú
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY 10031, United States of America
- Physics Program, Graduate Center, City University of New York, New York, NY 10016, United States of America
| | - Yiling Yu
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Dragomir Neshev
- ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS), Department of Electronic Materials Engineering, Research School of Physics, The Australian National University, Canberra, ACT 2601, Australia
| | - Andrey E Miroshnichenko
- School of Engineering and Information Technology, University of New South Wales, Canberra, ACT, 2600, Australia
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Zheng P, Raj P, Mizutani T, Szabo M, Hanson WA, Barman I. Plexcitonic Quasi-Bound States in the Continuum. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2102596. [PMID: 34411423 PMCID: PMC8487958 DOI: 10.1002/smll.202102596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/21/2021] [Indexed: 05/18/2023]
Abstract
Enhancing light-matter interactions is fundamental to the advancement of nanophotonics and optoelectronics. Yet, light diffraction on dielectric platforms and energy loss on plasmonic metallic systems present an undesirable trade-off between coherent energy exchange and incoherent energy damping. Through judicious structural design, both light confinement and energy loss issues could be potentially and simultaneously addressed by creating bound states in the continuum (BICs) where light is ideally decoupled from the radiative continuum. Herein, the authors present a general framework based on the two-coupled resonances to first conceptualize and then numerically demonstrate a type of quasi-BICs that can be achieved through the interference between two bare resonance modes and is characterized by the considerably narrowed spectral line shape even on lossy metallic nanostructures. The ubiquity of the proposed framework further allows the paradigm to be extended for the realization of plexcitonic quasi-BICs on the same metallic systems. Owing to the topological nature, both plasmonic and plexcitonic quasi-BICs display strong mode robustness against parameters variation, thereby providing an attractive platform to unlock the potential of the coupled plasmon-exciton systems for manipulation of the photophysical properties of condensed phases.
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Affiliation(s)
- Peng Zheng
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, United States
- To whom the correspondence should be addressed. ;
| | - Piyush Raj
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, United States
| | - Takayuki Mizutani
- Beckman Coulter Diagnostics – Immunoassay Business Unit, 1000 Lake Hazeltine Dr, Chaska, MN 55318
| | - Miklos Szabo
- Beckman Coulter Diagnostics – Immunoassay Business Unit, 1000 Lake Hazeltine Dr, Chaska, MN 55318
| | - William A. Hanson
- Beckman Coulter Diagnostics – Immunoassay Business Unit, 1000 Lake Hazeltine Dr, Chaska, MN 55318
| | - Ishan Barman
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, United States
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States
- To whom the correspondence should be addressed. ;
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Zheng Z, Zhu Y, Duan J, Qin M, Wu F, Xiao S. Enhancing Goos-Hänchen shift based on magnetic dipole quasi-bound states in the continuum in all-dielectric metasurfaces. OPTICS EXPRESS 2021; 29:29541-29549. [PMID: 34615062 DOI: 10.1364/oe.438180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
Metasurface-mediated bound states in the continuum (BIC) provides a versatile platform for light manipulation at the subwavelength dimension with diverging radiative quality factor and extreme optical localization. In this work, we theoretically propose the magnetic dipole quasi-BIC resonance in asymmetric silicon nanobar metasurfaces to realize giant Goos-Hänchen (GH) shift enhancement by more than three orders of wavelength. In sharp contrast to GH shift based on the Brewster dip or transmission-type resonance, the maximum GH shift here is located at the reflection peak with unity reflectance, which can be conveniently detected in the experiment. By adjusting the asymmetric parameter of metasurfaces, the Q-factor and GH shift can be modulated accordingly. More interestingly, it is found that GH shift exhibits an inverse quadratic dependence on the asymmetric parameter. Furthermore, we theoretically design an ultrasensitive environmental refractive index sensor based on the quasi-BIC enhanced GH shift, with a maximum sensitivity of 1.5×107 μm/RIU. Our work not only reveals the essential role of BIC in engineering the basic optical phenomena but also suggests the way for pushing the performance limits of optical communication devices, information storage, wavelength division de/multiplexers, and ultrasensitive sensors.
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Qin M, Xiao S, Liu W, Ouyang M, Yu T, Wang T, Liao Q. Strong coupling between excitons and magnetic dipole quasi-bound states in the continuum in WS 2-TiO 2 hybrid metasurfaces. OPTICS EXPRESS 2021; 29:18026-18036. [PMID: 34154071 DOI: 10.1364/oe.427141] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/17/2021] [Indexed: 06/13/2023]
Abstract
Enhancing the light-matter interactions in two-dimensional materials via optical metasurfaces has attracted much attention due to its potential to enable breakthrough in advanced compact photonic and quantum information devices. Here, we theoretically investigate a strong coupling between excitons in monolayer WS2 and quasi-bound states in the continuum (quasi-BIC). In the hybrid structure composed of WS2 coupled with asymmetric titanium dioxide nanobars, a remarkable spectral splitting and typical anticrossing behavior of the Rabi splitting can be observed, and such strong coupling effect can be modulated by shaping the thickness and asymmetry parameter of the proposed metasurfaces, and the angle of incident light. It is found that the balance of line width of the quasi-BIC mode and local electric field enhancement should be considered since both of them affect the strong coupling, which is crucial to the design and optimization of metasurface devices. This work provides a promising way for controlling the light-matter interactions in strong coupling regime and opens the door for the future novel quantum, low-energy, distinctive nanodevices by advanced meta-optical engineering.
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Liu T, Zhou C, Xiao S. Gain-assisted critical coupling for enhanced optical absorption in graphene. NANOTECHNOLOGY 2021; 32:205202. [PMID: 33635831 DOI: 10.1088/1361-6528/abe5dc] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Enhanced optical absorption in two-dimensional (2D) materials has recently moved into the focus of nanophotonics research. In this work, we present a gain-assisted method to achieve critical coupling and demonstrate the maximum absorption in undoped monolayer graphene in the near-infrared. In a two-port system composed of photonic crystal slab loaded with graphene, the gain medium is introduced to adjust the dissipative rate to match the radiation rate for the critical coupling, which is accessible without changing the original structural geometry. The appropriate tuning of the gain coefficient also enables the critical coupling absorption within a wide wavelength regime for different coupling configurations. This work provides a powerful guide to manipulate light-matter interaction in 2D materials and opens up a new path to design ultra-compact and high-performance 2D material optical devices.
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Affiliation(s)
- Tingting Liu
- Laboratory of Millimeter Wave and Terahertz Technology, School of Physics and Electronics Information, Hubei University of Education, Wuhan 430205, People's Republic of China
| | - Chaobiao Zhou
- College of Mechanical and Electronic Engineering, Guizhou Minzu University, Guiyang 550025, People's Republic of China
| | - Shuyuan Xiao
- Institute for Advanced Study, Nanchang University, Nanchang 330031, People's Republic of China
- Jiangxi Key Laboratory for Microscale Interdisciplinary Study, Nanchang University, Nanchang 330031, People's Republic of China
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