Large second-harmonic vortex beam generation with quasi-nonlinear spin–orbit interaction

作     者：Wenchao Zhao Kai Wang Xuanmiao Hong Bingxia Wang Xiaobo Han Kun Wang Weiwei Liu Hua Long Bing Wang Peixiang Lu 赵文超;王凯;洪玄淼;王炳霞;韩晓博;王坤;刘为为;龙华;王兵;陆培祥

作者机构：Wuhan National Laboratory for Optoelectronics and School of PhysicsHuazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory of Optical Information and Pattern RecognitionWuhan Institute of TechnologyWuhan 430205China Guangdong Intelligent Robotics InstituteDongguan 523808China CAS Center for Excellence in Ultra-intense Laser ScienceShanghai 201800China 

出 版 物：《Science Bulletin》 (科学通报（英文版）)

年 卷 期：2021年第66卷第5期

页      面：449-456,M0004页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：This work was supported by the National Natural Science Foundation of China(91850113,11774115 and 11904271) the National Basic Research Program of China(2014CB921301) the Basic and Applied Basic Research Major Program of Guangdong Province(2019B030302003) 

主　　题：Plasmonic metasurface Orbital-angular momentum Monolayer WS_(2) Second-harmonic generation Metalenses 

摘      要：A harmonic vortex beam is a typical vector beam with a helical wavefront at harmonic frequencies(e.g.,second and third harmonics). It provides an additional degree of freedom beyond spin-and orbitalangular momentum, which may greatly increase the capacity for communicating and encoding information. However, conventional harmonic vortex beam generators suffer from complex designs and a low nonlinear conversion efficiency. Here, we propose and experimentally demonstrate the generation of a large second-harmonic(SH) vortex beam with quasi-nonlinear spin–orbit interaction(SOI). Highquality SH vortex beams with large topological charges up to 28 are realized experimentally. This indicated that the quasi-angular-momentum of a plasmonic spiral phase plate at the excitation wavelength(topological charge, q) could be imprinted on the harmonic signals from the attached WS2 monolayer. The generated harmonic vortex beam has a topological charge of l_(n)= 2 nq(n is the harmonic order). The results may open new avenues for generating harmonic optical vortices for optical communications and enables novel multi-functional hybrid metasurface devices to manipulate harmonic beams.