大视场角、等衍射角间隔的矢量超构表面分束器  

Metasurface beamsplitter with large field of view and equal diffraction angle interval

作　　者：夏睿星 赵东 李子勤 黄坤 Xia Ruixing;Zhao Dong;Li Ziqin;Huang Kun(Department of Optics and Optical Engineering,School of Physics,University of Science and Technology of China,Hefei,Anhui 230026,china)

机构地区：[1]中国科学技术大学物理学院光学与光学工程系,安徽合肥230026

出　　处：《光电工程》2024年第8期136-144,共9页Opto-Electronic Engineering

基　　金：国家重点研发计划(2022YFB3607300);国家自然科学基金资助项目(62322512);中国博士后科学基金资助项目(2023M743364)。

摘　　要：激光雷达目前主要使用达曼光栅实现激光分束。然而,达曼光栅作为周期性衍射光学器件需要满足光栅方程,其各衍射角的正弦值成等差数列,无法实现均匀的角度分束,同时理论衍射效率受到限制。本文将角谱法和随机搜索算法结合,设计了一种非周期性红外超构表面激光分束器。该分束器可实现70°的分束全角等角度间隔的41分束。其理论衍射效率达84%,高于二元相位器件的理论极限。在实验测试中,超构表面分束器具有较好的分束均匀性,可促进激光雷达的发展。LiDAR currently mainly uses a Dammann grating as the laser beamsplitter.However,as a periodic diffraction optical device,the Dammann grating satisfies the grating equation requiring each diffraction angle's sine value to form an arithmetic progression,which cannot achieve uniform angular beam-splitting.The theoretical diffraction efficiency is also limited.This paper uses the angular spectrum and random search optimization algorithm to design a more flexible non-periodic beamsplitter.Simulations show that the metasurface beamsplitter can achieve a 70-degree field angle of 41 beams with an equal diffraction angle interval.The simulated diffraction efficiency reaches 84%which is higher than the diffraction limit of a binary phase device.In experiments,the metasurface beamsplitter has good beam-splitting uniformity and can promote the development of LiDAR.

关 键 词：超构表面 分束 达曼光栅 衍射光学元件 

分 类 号：O439[机械工程—光学工程]