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Guo WP, Liang WY, Cheng CW, Wu WL, Wang YT, Sun Q, Zu S, Misawa H, Cheng PJ, Chang SW, Ahn H, Lin MT, Gwo S. Chiral Second-Harmonic Generation from Monolayer WS 2/Aluminum Plasmonic Vortex Metalens. Nano Lett 2020; 20:2857-2864. [PMID: 32163291 DOI: 10.1021/acs.nanolett.0c00645] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Two-dimensional spiral plasmonic structures have emerged as a versatile approach to generate near-field vortex fields with tunable topological charges. We demonstrate here a far-field approach to observe the chiral second-harmonic generation (SHG) at designated visible wavelengths from a single plasmonic vortex metalens. This metalens comprises an Archimedean spiral slit fabricated on atomically flat aluminum epitaxial film, which allows for precise tuning of plasmonic resonances and subsequent transfer of two-dimensional materials on top of the spiral slit. The nonlinear optical measurements show a giant SHG circular dichroism. Furthermore, we have achieved an enhanced chiral SHG conversion efficiency (about an order of magnitude greater than the bare aluminum lens) from monolayer tungsten disulfide (WS2)/aluminum metalens, which is designed at the C-exciton resonance of WS2. Since the C-exciton is not a valley exciton, the enhanced chiral SHG in this hybrid system originates from the plasmonic vortex field-enhanced SHG under the optical spin-orbit interaction.
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Affiliation(s)
- Wan-Ping Guo
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Wei-Yun Liang
- Department of Photonics, College of Electrical and Computer Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan
| | - Chang-Wei Cheng
- Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Wei-Lin Wu
- Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Yen-Ting Wang
- Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan
| | - Quan Sun
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Shuai Zu
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Hiroaki Misawa
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
- Center for Emergent Functional Matter Science, National Chiao-Tung University, Hsinchu 30010, Taiwan
| | - Pi-Ju Cheng
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Shu-Wei Chang
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Hyeyoung Ahn
- Department of Photonics, College of Electrical and Computer Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan
| | - Minn-Tsong Lin
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Shangjr Gwo
- Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
- Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan
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