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Chen Y, Zheng X, Zhang X, Pan W, Wang Z, Li S, Dong S, Liu F, He Q, Zhou L, Sun S. Efficient Meta-couplers Squeezing Propagating Light into On-Chip Subwavelength Devices in a Controllable Way. NANO LETTERS 2023; 23:3326-3333. [PMID: 37026788 DOI: 10.1021/acs.nanolett.3c00310] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
On-chip photonic systems play crucial roles in nanoscience and nanoapplications, but coupling external light to these subwavelength devices is challenging due to a large mode mismatch. Here, we establish a new scheme for realizing highly miniaturized couplers for efficiently exciting on-chip photonic devices in a controllable way. Relying on both resonant and Pancharatnam-Berry mechanisms, our meta-device can couple circularly polarized light to a surface plasmon, which is then focused into a spot placed with a target on-chip device. We experimentally demonstrate two meta-couplers. The first can excite an on-chip waveguide (with a 0.1λ × 0.2λ cross section) with an absolute efficiency of 51%, while the second can achieve incident spin-selective excitation of a dual-waveguide system. Background-free excitation of a gap-plasmon nanocavity with the local field enhanced by >1000 times is numerically demonstrated. Such a scheme connects efficiently propagating light in free space and localized fields in on-chip devices, being highly favored in many integration-optics applications.
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Affiliation(s)
- Yizhen Chen
- Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China
- Yiwu Research Institute of Fudan University, Chengbei Road, Yiwu 322000, Zhejiang, China
| | - Xiaoying Zheng
- State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Xiyue Zhang
- State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Weikang Pan
- Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China
- Yiwu Research Institute of Fudan University, Chengbei Road, Yiwu 322000, Zhejiang, China
| | - Zhuo Wang
- State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Shiqing Li
- Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China
- Yiwu Research Institute of Fudan University, Chengbei Road, Yiwu 322000, Zhejiang, China
| | - Shaohua Dong
- Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China
- Yiwu Research Institute of Fudan University, Chengbei Road, Yiwu 322000, Zhejiang, China
| | - Feifei Liu
- State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
- College Physics & Materials Science, Tianjin Normal University, Tianjin 300387, China
| | - Qiong He
- State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Lei Zhou
- State Key Laboratory of Surface Physics and Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
| | - Shulin Sun
- Shanghai Engineering Research Centre of Ultra Precision Optical Manufacturing, Department of Optical Science and Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China
- Yiwu Research Institute of Fudan University, Chengbei Road, Yiwu 322000, Zhejiang, China
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Wang Y, Jia J, Zhang J, Xiao R, Xu W, Feng Y. Modulating the Charge Transfer Plasmon in Bridged Au Core-Satellite Homometallic Nanostructures. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2207907. [PMID: 37052515 DOI: 10.1002/smll.202207907] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 03/17/2023] [Indexed: 06/19/2023]
Abstract
The localized surface plasmon resonance (LSPR) is one of the important properties for noble metal nanoparticles. Tuning the LSPR on demand thus has attracted tremendous interest. Beyond the size and shape control, manipulating intraparticle coupling is an effective way to tailor their LSPR. The charge transfer plasmon (CTP) is the most important mode of conductive coupling between subunits linked by conductive bridges that are well studied for structures prepared on substrates by lithography method. However, the colloidal synthesis of CTP structure remains a great challenge. This work reports the colloidal synthesis of extraordinary bridged Au core-satellite structures by exploiting the buffer effect of polydopamine shell on Au core for Au atom diffusion, in which the Au bridge is well controlled in terms of width and length. Benefiting from the tunable Au bridges, the resonance energy of the CTP can be readily controlled. As a result, the LSPR absorptions of the core-satellite structures are continuously tuned within the NIR spectral range (from 900 to >1300 nm), demonstrating their great potentials for ultrafast nano-optics and biomedical applications.
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Affiliation(s)
- Yun Wang
- Institute of Advanced Synthesis (IAS), School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Jia Jia
- Institute of Advanced Synthesis (IAS), School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Jie Zhang
- Institute of Advanced Synthesis (IAS), School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Ruixue Xiao
- Institute of Advanced Synthesis (IAS), School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Wenjia Xu
- Institute of Advanced Synthesis (IAS), School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
- School of Physical and Mathematical Sciences, Nanjing Tech University, Nanjing, 211816, P. R. China
| | - Yuhua Feng
- Institute of Advanced Synthesis (IAS), School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing, 211816, P. R. China
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Li F, Yang ZY, Shi JJ, He XB. Subwavelength dichroic demultiplexer based on double Fabry-Perot cavities. OPTICS EXPRESS 2022; 30:37753-37759. [PMID: 36258357 DOI: 10.1364/oe.472582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023]
Abstract
Plasmonic demultiplexers hold promise for the realization of the subwavelength and high-splitting ratio dichroic splitter and have a wide range of applications from optical communication, and manipulation to ultrafast data treatment. However, this vision has not been realized for a long time due to lacking the suitable splitting structure design, which limits its further development of integrated photonic circuits. Here, we demonstrate a plasmonic demultiplexer with subwavelength feature size (0.54 µm) and broadband spectral (620-870 nm) range, and high-splitting ratio (17 dB in experiments and 20 dB in calculations). It consists of two adjacent Fabry-Perot cavities (covered by PMMA polymer) and coupling gratings, which are integrated with the Au waveguide. The relatively simple double cavities design of our device has a simple theoretical analysis and fabrication process. Our work has relevance for various optical applications, such as multiple wavelength photodetectors and optical multichannel interconnects.
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Wu X, Wang Y. A physics-based machine learning approach for modeling the complex reflection coefficients of metal nanowires. NANOTECHNOLOGY 2022; 33:205701. [PMID: 35108696 DOI: 10.1088/1361-6528/ac512e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Metal nanowires are attractive building blocks for next-generation plasmonic devices with high performance and compact footprint. The complex reflection coefficients of the plasmonic waveguides are crucial for estimation of the resonating, lasing, or sensing performance. By incorporating physics-guided objective functions and constraints, we propose a simple approach to convert the specific reflection problem of nanowires to a universal regression problem. Our approach is able to efficiently and reliably determine both the reflectivity and reflection phase of the metal nanowires with arbitrary geometry parameters, working environments, and terminal shapes, merging the merits of the physics-based modeling and the data-driven modeling. The results may provide valuable reference for building comprehensive datasets of plasmonic architectures, facilitating theoretical investigations and large-scale designs of nanophotonic components and devices.
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Affiliation(s)
- Xiaoqin Wu
- Key Laboratory of Optoelectronic Technology & Systems (Ministry of Education), College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, People's Republic of China
| | - Yipei Wang
- Key Laboratory of Optoelectronic Technology & Systems (Ministry of Education), College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, People's Republic of China
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5
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Liaw JW, Mao SY, Luo JY, Ku YC, Kuo MK. Surface plasmon polaritons of higher-order mode and standing waves in metallic nanowires. OPTICS EXPRESS 2021; 29:18876-18888. [PMID: 34154134 DOI: 10.1364/oe.425958] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
The surface plasmon polaritons (SPPs) of higher-order mode propagating along a plasmonic nanowire (NW) or an elongated nanorod (NR) are studied theoretically. The dispersion relations of SPPs in NWs of different radii, obtained from a transcendental equation, show that the propagation lengths of SPPs of mode 1 and 2 at a specific frequency are longer than that of mode 0. For the higher-order mode, the spatial phase of the longitudinal component of electric field at a cross section of a NW exhibits the topological singularity, which indicates the optical vortex. Of importance, the streamlines of Poynting vector of these SPPs exhibit a helical winding along NW, and the azimuthal component of orbital momentum density exists in the nearfield of NW to produce a longitudinal orbital angular momentum (OAM). Two types of standing wave of counter-propagating SPPs of mode 1 and 2 are also studied; they perform as a string of beads or twisted donut depending on whether the handedness of two opposite-direction propagating SPPs is same or opposite. In addition, a SPP of mode 1 propagating along an elongated NR can be generated by means of an end-fire excitation of crossed electric bi-dipole with 90° phase difference. If the criterion of a resonator for a mode-1 standing wave (string of beads) is met, the configuration of a plasmonic NR associated with a pair of bi-dipoles with a phase delay (0° or 180°) at the two ends can be applied as a high-efficiency nanoantenna of transmission. Our results may pave a way to the further study of SPPs of higher-order mode carrying OAM along plasmonic waveguides.
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Shi J, Li Y, Kang M, He X, Halas NJ, Nordlander P, Zhang S, Xu H. Efficient Second Harmonic Generation in a Hybrid Plasmonic Waveguide by Mode Interactions. NANO LETTERS 2019; 19:3838-3845. [PMID: 31125243 DOI: 10.1021/acs.nanolett.9b01004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Developing highly efficient nanoscale coherent light sources is essential for advances in technological applications such as integrated photonic circuits, bioimaging, and sensing. An on-chip wavelength convertor based on second harmonic generation (SHG) would be a crucial step toward this goal, but the light-conversion efficiency would be low for small device dimensions. Here we demonstrate strongly enhanced SHG with a high conversion efficiency of 4 × 10-5 W-1 from a hybrid plasmonic waveguide consisting of a CdSe nanowire coupled with a Au film. The strong spatial overlap of the waveguide mode with the nonlinear material and momentum conservation between the incident and reflected modes are the key factors resulting in such high efficiency. The SHG emission angles vary linearly with excitation wavelength, indicating a nonlinear steering of coherent light emission at the subwavelength scale. Our work is promising for the realization of efficient and tunable nonlinear coherent sources and opens new approaches for efficient integrated nonlinear nanophotonic devices.
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Affiliation(s)
- Junjun Shi
- The Institute for Advanced Studies , Wuhan University , Wuhan 430072 , China
| | - Yang Li
- School of Physics and Technology, Center for Nanoscience and Nanotechnology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education , Wuhan University , Wuhan 430072 , China
| | - Meng Kang
- School of Physics and Technology, Center for Nanoscience and Nanotechnology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education , Wuhan University , Wuhan 430072 , China
| | - Xiaobo He
- School of Physics and Technology, Center for Nanoscience and Nanotechnology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education , Wuhan University , Wuhan 430072 , China
| | - Naomi J Halas
- Department of Physics and Astronomy, Department of Electrical and Computer Engineering and Laboratory for Nanophotonics , Rice University , Houston , Texas 77005 , United States
| | - Peter Nordlander
- Department of Physics and Astronomy, Department of Electrical and Computer Engineering and Laboratory for Nanophotonics , Rice University , Houston , Texas 77005 , United States
| | - Shunping Zhang
- School of Physics and Technology, Center for Nanoscience and Nanotechnology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education , Wuhan University , Wuhan 430072 , China
| | - Hongxing Xu
- The Institute for Advanced Studies , Wuhan University , Wuhan 430072 , China
- School of Physics and Technology, Center for Nanoscience and Nanotechnology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education , Wuhan University , Wuhan 430072 , China
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7
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Wei H, Pan D, Zhang S, Li Z, Li Q, Liu N, Wang W, Xu H. Plasmon Waveguiding in Nanowires. Chem Rev 2018; 118:2882-2926. [DOI: 10.1021/acs.chemrev.7b00441] [Citation(s) in RCA: 142] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Hong Wei
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Deng Pan
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Shunping Zhang
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
| | - Zhipeng Li
- Beijing Key Laboratory of Nano-Photonics and Nano-Structure (NPNS), Department of Physics, Capital Normal University, Beijing 100048, China
| | - Qiang Li
- Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China
| | - Ning Liu
- Department of Physics and Bernal Institute, University of Limerick, Limerick, Ireland
| | - Wenhui Wang
- School of Science, Xi’an Jiaotong University, Xi’an 710049, China
| | - Hongxing Xu
- School of Physics and Technology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China
- Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
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8
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Hua J, Wu F, Xu Z, Wang W. Influence of symmetry breaking degrees on surface plasmon polaritons propagation in branched silver nanowire waveguides. Sci Rep 2016; 6:34418. [PMID: 27677403 PMCID: PMC5039628 DOI: 10.1038/srep34418] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/13/2016] [Indexed: 11/09/2022] Open
Abstract
Surface plasmon polaritons (SPPs)-based nanowire (NW) waveguides demonstrate promising potentials in the integrated nanophotonic circuits and devices. The realization of controlling SPPs propagation in NWs is significant for the performance of nanophotonic devices when employed for special function. In this work, we report the effect of symmetry breaking degrees on SPPs propagation behavior in manually fabricated branched silver NW structures. The symmetry breaking degree can be tuned by the angle between main NW and branch NW, which influences the emissions at the junction and the main NW terminal in a large extent. Our results illustrate the significance of symmetry breaking degree on SPPs propagation in NW-based waveguides which is crucial for designing the future nanophotonic circuits.
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Affiliation(s)
- Jiaojiao Hua
- School of science, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Fan Wu
- School of science, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Zhongfeng Xu
- School of science, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Wenhui Wang
- School of science, Xi'an Jiaotong University, Xi'an, 710049, China
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9
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Sankaran KJ, Hoang DQ, Kunuku S, Korneychuk S, Turner S, Pobedinskas P, Drijkoningen S, Van Bael MK, D' Haen J, Verbeeck J, Leou KC, Lin IN, Haenen K. Enhanced optoelectronic performances of vertically aligned hexagonal boron nitride nanowalls-nanocrystalline diamond heterostructures. Sci Rep 2016; 6:29444. [PMID: 27404130 PMCID: PMC4941520 DOI: 10.1038/srep29444] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/13/2016] [Indexed: 01/31/2023] Open
Abstract
Field electron emission (FEE) properties of vertically aligned hexagonal boron nitride nanowalls (hBNNWs) grown on Si have been markedly enhanced through the use of nitrogen doped nanocrystalline diamond (nNCD) films as an interlayer. The FEE properties of hBNNWs-nNCD heterostructures show a low turn-on field of 15.2 V/μm, a high FEE current density of 1.48 mA/cm(2) and life-time up to a period of 248 min. These values are far superior to those for hBNNWs grown on Si substrates without the nNCD interlayer, which have a turn-on field of 46.6 V/μm with 0.21 mA/cm(2) FEE current density and life-time of 27 min. Cross-sectional TEM investigation reveals that the utilization of the diamond interlayer circumvented the formation of amorphous boron nitride prior to the growth of hexagonal boron nitride. Moreover, incorporation of carbon in hBNNWs improves the conductivity of hBNNWs. Such a unique combination of materials results in efficient electron transport crossing nNCD-to-hBNNWs interface and inside the hBNNWs that results in enhanced field emission of electrons. The prospective application of these materials is manifested by plasma illumination measurements with lower threshold voltage (370 V) and longer life-time, authorizing the role of hBNNWs-nNCD heterostructures in the enhancement of electron emission.
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Affiliation(s)
| | - Duc Quang Hoang
- Institute for Materials Research (IMO), Hasselt University, 3590 Diepenbeek, Belgium.,IMOMEC, IMEC vzw, 3590 Diepenbeek, Belgium
| | - Srinivasu Kunuku
- Department of Engineering and System Science, National Tsing Hua University, 30013 Hsinchu, Taiwan
| | - Svetlana Korneychuk
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, 2020 Antwerp, Belgium
| | - Stuart Turner
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, 2020 Antwerp, Belgium
| | - Paulius Pobedinskas
- Institute for Materials Research (IMO), Hasselt University, 3590 Diepenbeek, Belgium.,IMOMEC, IMEC vzw, 3590 Diepenbeek, Belgium
| | - Sien Drijkoningen
- Institute for Materials Research (IMO), Hasselt University, 3590 Diepenbeek, Belgium.,IMOMEC, IMEC vzw, 3590 Diepenbeek, Belgium
| | - Marlies K Van Bael
- Institute for Materials Research (IMO), Hasselt University, 3590 Diepenbeek, Belgium.,IMOMEC, IMEC vzw, 3590 Diepenbeek, Belgium
| | - Jan D' Haen
- Institute for Materials Research (IMO), Hasselt University, 3590 Diepenbeek, Belgium.,IMOMEC, IMEC vzw, 3590 Diepenbeek, Belgium
| | - Johan Verbeeck
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, 2020 Antwerp, Belgium
| | - Keh-Chyang Leou
- Department of Engineering and System Science, National Tsing Hua University, 30013 Hsinchu, Taiwan
| | - I-Nan Lin
- Department of Physics, Tamkang University, 251 Tamsui, Taiwan
| | - Ken Haenen
- Institute for Materials Research (IMO), Hasselt University, 3590 Diepenbeek, Belgium.,IMOMEC, IMEC vzw, 3590 Diepenbeek, Belgium
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Johns P, Yu K, Devadas MS, Hartland GV. Role of Resonances in the Transmission of Surface Plasmon Polaritons between Nanostructures. ACS NANO 2016; 10:3375-3381. [PMID: 26866536 DOI: 10.1021/acsnano.5b07185] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Understanding how surface plasmon polaritons (SPPs) propagate in metal nanostructures is important for the development of plasmonic devices. In this paper, we study the transmission of SPPs between single-crystal gold nanobars on a glass substrate using transient absorption microscopy. The coupled structures were produced by creating gaps in single nanobars by focused ion beam milling. SPPs were launched by focusing the pump laser at the end of the nanobar, and the transmission across the gaps was imaged by scanning the probe laser over the nanostructure. The results show larger losses at small gap sizes. Finite element method calculations were used to investigate this effect. The calculations show two main modes for nanobars on a glass surface: a leaky mode localized at the air-gold interface, and a bound mode localized at the glass-gold interface. At specific gap sizes (approximately 50 nm for our system), these SPP modes can excite localized surface plasmon modes associated with the gap, which dissipate energy. This increases the energy losses at small gap sizes. Experiments and simulations were also performed for the nanobars in microscope immersion oil, which creates a more homogeneous optical environment, and consistent results were observed.
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Affiliation(s)
- Paul Johns
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Kuai Yu
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Mary Sajini Devadas
- Department of Chemistry, Towson University , Towson, Maryland 21252, United States
| | - Gregory V Hartland
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
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11
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Yang L, Wang H, Fang Y, Li Z. Polarization State of Light Scattered from Quantum Plasmonic Dimer Antennas. ACS NANO 2016; 10:1580-1588. [PMID: 26700823 DOI: 10.1021/acsnano.5b07223] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Plasmonic antennas are able to concentrate and re-emit light in a controllable manner through strong coupling between metallic nanostructures. Only recently has it found that quantum mechanical effects can drastically change the coupling strength as the feature size approaches atomic scales. Here, we present a comprehensive experimental and theoretical study of the evolution of the resonance peak and its polarization state as the dimer-antenna gap narrows to subnanometer scale. We clearly can identify the classical plasmonic regime, a crossover regime where nonlocal screening plays an important role, and the quantum regime where a charge transfer plasmon appears due to interparticle electron tunneling. Moreover, as the gap decreases from tens of to a few nanometers, the bonding dipole mode tends to emit photons with increasing polarizability. When the gap narrows to quantum regime, a significant depolarization of the mode emission is observed due to the reduction of the charge density of coupled quantum plasmons. These results would be beneficial for the understanding of quantum effects on emitting-polarization of nanoantennas and the development of quantum-based photonic nanodevices.
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Affiliation(s)
- Longkun Yang
- The Beijing Key Laboratory for Nano-Photonics and Nano-Structure (NPNS), Center for Condensed Matter Physics, Department of Physics, Capital Normal University , Beijing 100048, PR China
| | - Hancong Wang
- The Beijing Key Laboratory for Nano-Photonics and Nano-Structure (NPNS), Center for Condensed Matter Physics, Department of Physics, Capital Normal University , Beijing 100048, PR China
| | - Yan Fang
- The Beijing Key Laboratory for Nano-Photonics and Nano-Structure (NPNS), Center for Condensed Matter Physics, Department of Physics, Capital Normal University , Beijing 100048, PR China
| | - Zhipeng Li
- The Beijing Key Laboratory for Nano-Photonics and Nano-Structure (NPNS), Center for Condensed Matter Physics, Department of Physics, Capital Normal University , Beijing 100048, PR China
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