標題: Plasmonic Enhancement and Manipulation of Optical Nonlinearity in Monolayer Tungsten Disulfide
作者: Shi, Jinwei
Liang, Wei-Yun
Raja, Soniya S.
Sang, Yungang
Zhang, Xin-Quan
Chen, Chun-An
Wang, Yanrong
Yang, Xinyue
Lee, Yi-Hsien
Ahn, Hyeyoung
Gwo, Shangjr
光電工程學系
Department of Photonics
關鍵字: 2D materials;nonlinear optics;plasmonic metasurfaces;second-harmonic generation;transition metal dichalcogenides
公開日期: 1-Oct-2018
摘要: Monolayer transition metal dichalcogenides (TMDCs) have large second-order optical nonlinearity owing to broken inversion symmetry in two-dimensional (2D) crystals. However, despite the strong light-matter coupling in monolayer TMDCs, their nonlinear responses are ultimately limited by subnanometer thickness. Here, a dramatic enhancement of the second-harmonic generation (SHG) is achieved from monolayer tungsten disulfide (WS2) incorporated onto a 2D silver (Ag) nanogroove grating with subwavelength pitch. By tuning surface plasmon mode and second-harmonic frequency in resonance with the C exciton in WS2, a large SHG enhancement factor (approximate to 400) and a large conversion efficiency (approximate to 2.0 x 10(-5)) can be obtained. Furthermore, the azimuthal angle dependence of polarized SHG from monolayer WS2 can be manipulated by the nanogroove plasmonic mode. Based on this property, a polarization-modulated optical encoding technique is demonstrated. The results suggest that 2D TMDC-plasmonic hybrid metasurface structures can provide an ideal integration platform for on-chip nonlinear photonics and plasmonics.
URI: http://dx.doi.org/10.1002/lpor.201800188
http://hdl.handle.net/11536/148273
ISSN: 1863-8880
DOI: 10.1002/lpor.201800188
期刊: LASER & PHOTONICS REVIEWS
Volume: 12
Appears in Collections:Articles