Vortex-field enhancement through high-threshold geometric metasurface  

作　　者：Qingsong Wang Yao Fang Yu Meng Han Hao Xiong Li Mingbo Pu Xiaoliang Ma Xiangang Luo 

机构地区：[1]National Key Laboratory of Optical Field Manipulation Science and Technology,Chinese Academy of Sciences,Chengdu 610209,China [2]State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering,Institute of Optics and Electronics,Chinese Academy of Sciences,Chengdu 610209,China [3]College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China [4]Research Center on Vector Optical Fields,Institute of Optics and Electronics,Chinese Academy of Sciences,Chengdu 610209,China

出　　处：《Opto-Electronic Advances》2024年第12期79-90,共12页光电进展(英文)

基　　金：financial supports from the National Key Research and Development Program(Grant No.2018YFA0701800);the National Natural Science Foundation of China(NSFC)(Grant No.62192773);the West Light Foundation of Chinese Academy of Sciences(Grant No.xbzg-zdsys-202307).

摘　　要：Intense vortex beam is expected to empower captivating phenomena and applications in high power laser-matter interac-tions.Currently,the superposition of multiple vortex beams has shown the unique ability to tailor and enhance the vortex field.However,traditional strategies to generate such beams suffer from large volume or/and low laser-induced damage threshold,hindering the practical widespread applications.Herein,a single high-threshold metasurface is proposed and experimentally demonstrated for the generation and superposition of multiple collinear vortex beams.This scheme takes advantage of the high conversion efficiency of phase-only modulation in the metasurface design by adopting the concept of a sliced phase pattern in the azimuthal direction.An optical hot spot with an enhanced intensity and steady spatial propagation is experimentally achieved.Moreover,femtosecond laser-induced birefringent nanostructures embedded in silica glass are utilized as the building block with high optical efficiency.Transmittance greater than 99.4%in the near-in-frared range and laser-induced damage threshold as high as 68.0 J/cm^(2)(at 1064 nm,6 ns)are experimentally verified.Considering these remarkable performances,the demonstrated high-threshold metasurface has promising applications in a host of high-power laser fields.

关 键 词：multiple vortex beams metasurface high-threshold birefringent nanostructures femtosecond laser 

分 类 号：O43[机械工程—光学工程]