標題: Chiral Second-Harmonic Generation from Monolayer WS2/Aluminum Plasmonic Vortex Metalens
作者: Guo, Wan-Ping
Liang, Wei-Yun
Cheng, Chang-Wei
Wu, Wei-Lin
Wang, Yen-Ting
Sun, Quan
Zu, Shuai
Misawa, Hiroaki
Cheng, Pi-Ju
Chang, Shu-Wei
Ahn, Hyeyoung
Lin, Minn-Tsong
Gwo, Shangjr
交大名義發表
電子物理學系
光電工程學系
National Chiao Tung University
Department of Electrophysics
Department of Photonics
關鍵字: Surface plasmonic vortex metalens;optical spin-orbit interaction;chiral nonlinearity;second-harmonic generation;aluminum epitaxial film;monolayer tungsten disulfide
公開日期: 8-Apr-2020
摘要: 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.
URI: http://dx.doi.org/10.1021/acs.nanolett.0c00645
http://hdl.handle.net/11536/154390
ISSN: 1530-6984
DOI: 10.1021/acs.nanolett.0c00645
期刊: NANO LETTERS
Volume: 20
Issue: 4
起始頁: 2857
結束頁: 2864
Appears in Collections:Articles