Binary diffractive lens with subwavelength focusing for terahertz imaging  

作　　者：宁冉 王大勇 戎路 赵洁 王云新 林述锋 Ran Ning;Dayong Wang;Lu Rong;Jie Zhao;Yunxin Wang;Shufeng Lin(Department of Physics and Optoelectronics Engineering,Faculty of Science,Beijing University of Technology,Bejing 100124,China;Beijing Engineering Research Center of Precision Measurement Technology and Instruments,Bejing 100124,China)

机构地区：[1]Department of Physics and Optoelectronics Engineering,Faculty of Science,Beijing University of Technology,Bejing 100124,China [2]Beijing Engineering Research Center of Precision Measurement Technology and Instruments,Bejing 100124,China

出　　处：《Chinese Optics Letters》2023年第3期13-18,共6页中国光学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.62220106005,62075001,and 62175004);the Science Foundation of Education Commission of Beijing(No.KZ202010005008)。

摘　　要：The converging lens is one of the key components in high-resolution terahertz imaging.In this Letter,a binary diffractive lens is proposed for the scanning imaging system working at 278.6 GHz,in which a convergent beam with a waist diameter of0.65 mm is generated,and 1 mm lateral imaging resolution is realized.This low-cost terahertz lens,constituted by concentric rings with different radii,is optimized by stimulated annealing algorithm and fabricated by three-dimensional printing.Compared with the conventional transmissive convex lens,higher resolution and enhanced imaging quality are achieved via smaller focal spot of the illumination beam.This type of lens would promote terahertz imaging closer to practical applications such as nondestructive testing and other scenarios.

关 键 词：aero-optical effects supersonic mixing layer RVGA OPDrms flow control 

分 类 号：TH74[机械工程—光学工程] O441.4[机械工程—仪器科学与技术]