基于光频梳的太赫兹器件面形测量技术研究  

Research on Surface Shape Measurement Technology of Terahertz Devices Based on Optical Frequency Comb

作　　者：韩冰 葛锦蔓 任心仪 李小军[2] 刘佳[2] 闫明 曾和平[1,3] Han Bing;Ge Ginman;Ren Xinyi;Li Xiaojun;Liu jia;Yan Ming;Zeng Heping(Siate Key Laboratory of Precision Spectroscopy Science and Technology,East China Normal University,Shanghai 200062,China;National Key Laboratory of Science and Technology on Space Microwave,China Academy of Space Technology,Xi'an 710100,Shaanxi,China;Chongqing Institute,East China Normal University,Chongqing 401147,China)

机构地区：[1]华东师范大学精密光谱科学与技术国家重点实验室,上海200062 [2]中国空间技术研究院西安分院空间微波技术国家级重点实验室,陕西西安710100 [3]华东师范大学重庆研究院,重庆401147

出　　处：《中国激光》2022年第17期30-36,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(11904283);空间微波技术国家级重点实验室稳定支持基金(HTKJ2020KL504013)。

摘　　要：利用双光梳飞行时间法对小口径太赫兹天线及反射器面形进行了三维测量。实验中,单像素点测量时间为8μs,纵向测量误差为1.3μm。相较于传统的激光干涉法,双光梳法兼具了模糊距离大、测量精度高以及数据更新快等优势,为微波/太赫兹器件的面形测量提供了新途径。Objective Microwave and terahertz(THz)devices,such as antennas and reflectors,are useful in communication,navigation,and remote sensing.The laser tracking and measuring technology plays an important role in characterizing microwave/THz devices,such as surface measuring.Laser tracking and measuring,which is based on laser interferometry,provides high spatial resolution and accuracy for precise surface topography measurements.However,it has limitations such as a limited dynamic range,a low update rate,and difficulty measuring absolute distance.A coherent light source with significantly advanced laser sensing and ranging is provided by an optical frequency comb,which is made up of a large number of equally spaced optical frequency lines(or comb teeth).Dual-comb-ranging interferometry,which uses two asynchronous optical combs to measure absolute distance,provides high precision,large ambiguity range,and high speed.This method,which does not use moving mirrors,demonstrates significant advantages in laser ranging and holographic imaging.The measurement process,however,can be time-consuming due to a camera’s limited frame read-out speed.As a result,the benefits of dual-comb technology have not been fully exploited in imaging applications.Furthermore,dual-comb interferometry is yet to be used to characterize THz devices.In this paper,the dual-comb technique,combined with high-speed two-dimensional scanning mirrors,is applied to the surface measuring of THz devices.The measurement time per pixel for a three-dimensional(3D)image with 2.5×105 pixel is about 8μs.The longitudinal measurement error is 1.3μm(reduced to 5 nm at 0.1 s integration time),and the ambiguity range can reach 300 m.The experimental results show that dual-comb imaging is a useful and reliable tool for measuring the surface of microwave/THz devices with high precision.Methods Two near-infrared electro-optic combs(EOC 1 and EOC 2)are used for constructing a dual-comb interferometer(Fig.1).Each EOC contains a Fabry-Perot phase modulator driven by a rad

关 键 词：测量 太赫兹 干涉 相干 成像系统 

分 类 号：O436[机械工程—光学工程] TN247[理学—光学]