Far-field optical imaging of topological edge states in zigzag plasmonic chains
Topological photonics mimicking topological insulators has recently attracted considerable attention. The Su–Schrieffer–Heeger (SSH) model, which is a fundamental topological system, has been experimentally demonstrated in many photonic systems owing to its simplicity. In particular, a zigzag chain,...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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De Gruyter
2022-02-01
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| Series: | Nanophotonics |
| Subjects: | |
| Online Access: | https://doi.org/10.1515/nanoph-2021-0648 |
| _version_ | 1797947961053806592 |
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| author | Moritake Yuto Ono Masaaki Notomi Masaya |
| author_facet | Moritake Yuto Ono Masaaki Notomi Masaya |
| author_sort | Moritake Yuto |
| collection | DOAJ |
| description | Topological photonics mimicking topological insulators has recently attracted considerable attention. The Su–Schrieffer–Heeger (SSH) model, which is a fundamental topological system, has been experimentally demonstrated in many photonic systems owing to its simplicity. In particular, a zigzag chain, which is described by the SSH model, shows intriguing functionality such as polarization-dependent switching of topological edge states. To date, the far-field imaging of topological edge states in plasmonic chains has not been reported because of the constraint imposed by the diffraction limit. In this study, we experimentally observed the photonic topological edge states of zigzag plasmonic chains composed of metal nanodiscs in the optical region through far-field imaging. Using a chain longer than the diffraction limit, light scattering from the two edges of the zigzag chains was resolved. In the case of such a long chain, it was revealed that tiny gaps of several nanometers between the discs, which are difficult to fabricate, are necessary. Therefore, we propose connected chains and investigate the effect of the shape of the connected part, which reveals that similar topological edge states can be obtained even in the connected chains. The polarization dependence of edge-state imaging showed switching of the systems in trivial and topological phases in the same zigzag chain. Far-field observations serve as an easy and effective tool for the investigation and application of photonic topological edge states. |
| first_indexed | 2024-04-10T21:34:57Z |
| format | Article |
| id | doaj.art-75d82afd75fb4494af94dd32af04e138 |
| institution | Directory Open Access Journal |
| issn | 2192-8614 |
| language | English |
| last_indexed | 2024-04-10T21:34:57Z |
| publishDate | 2022-02-01 |
| publisher | De Gruyter |
| record_format | Article |
| series | Nanophotonics |
| spelling | doaj.art-75d82afd75fb4494af94dd32af04e1382023-01-19T12:46:58ZengDe GruyterNanophotonics2192-86142022-02-011192183218910.1515/nanoph-2021-0648Far-field optical imaging of topological edge states in zigzag plasmonic chainsMoritake Yuto0Ono Masaaki1Notomi Masaya2Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo152-8550, JapanNTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi-shi243-0198, Kanagawa, JapanDepartment of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo152-8550, JapanTopological photonics mimicking topological insulators has recently attracted considerable attention. The Su–Schrieffer–Heeger (SSH) model, which is a fundamental topological system, has been experimentally demonstrated in many photonic systems owing to its simplicity. In particular, a zigzag chain, which is described by the SSH model, shows intriguing functionality such as polarization-dependent switching of topological edge states. To date, the far-field imaging of topological edge states in plasmonic chains has not been reported because of the constraint imposed by the diffraction limit. In this study, we experimentally observed the photonic topological edge states of zigzag plasmonic chains composed of metal nanodiscs in the optical region through far-field imaging. Using a chain longer than the diffraction limit, light scattering from the two edges of the zigzag chains was resolved. In the case of such a long chain, it was revealed that tiny gaps of several nanometers between the discs, which are difficult to fabricate, are necessary. Therefore, we propose connected chains and investigate the effect of the shape of the connected part, which reveals that similar topological edge states can be obtained even in the connected chains. The polarization dependence of edge-state imaging showed switching of the systems in trivial and topological phases in the same zigzag chain. Far-field observations serve as an easy and effective tool for the investigation and application of photonic topological edge states.https://doi.org/10.1515/nanoph-2021-0648nanofabricationnanophotonicsoptical imagingplasmonicstopological edge statestopological photonics |
| spellingShingle | Moritake Yuto Ono Masaaki Notomi Masaya Far-field optical imaging of topological edge states in zigzag plasmonic chains Nanophotonics nanofabrication nanophotonics optical imaging plasmonics topological edge states topological photonics |
| title | Far-field optical imaging of topological edge states in zigzag plasmonic chains |
| title_full | Far-field optical imaging of topological edge states in zigzag plasmonic chains |
| title_fullStr | Far-field optical imaging of topological edge states in zigzag plasmonic chains |
| title_full_unstemmed | Far-field optical imaging of topological edge states in zigzag plasmonic chains |
| title_short | Far-field optical imaging of topological edge states in zigzag plasmonic chains |
| title_sort | far field optical imaging of topological edge states in zigzag plasmonic chains |
| topic | nanofabrication nanophotonics optical imaging plasmonics topological edge states topological photonics |
| url | https://doi.org/10.1515/nanoph-2021-0648 |
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