基于反射式光栅对的THz-TDS色散补偿技术  

THz-TDS Dispersion Compensation Technology Based on Reflective Grating Pair

作　　者：王文博 牟达 崔宗宇[1,2] 杨帆 刘洋 张悦[1,2] 孙大成 Wang Wenbo;Mu Da;Cui Zongyu;Yang Fan;Liu Yang;Zhang Yue;Sun Dacheng(Key Laboratory of Photoelectric Measurement and Optical Information Transmission Technology of Ministry of Education,School of Opto-Electronic Engineering,Changchun University of Science and Technology,Changchun 130022,Jilin,China;National Demonstration Center for Experimental Opto-Electronic Engineering Education,School of Opto-Electronic Engineering,Changchun University of Science and Technology,Changchun 130022,Jilin,China)

机构地区：[1]长春理工大学光电工程学院光电测控与光信息传输技术教育部重点实验室,吉林长春130022 [2]长春理工大学光电工程学院光电工程国家级教学示范中心,吉林长春130022

出　　处：《光学学报》2022年第14期26-31,共6页Acta Optica Sinica

基　　金：吉林省科技资源开放共享服务平台与科研条件保障项目(20191004022TC);吉林省科技发展计划(201506230147C)。

摘　　要：为解决飞秒激光脉冲在光纤中传输的色散效应引起的太赫兹波泵浦效率低的问题,针对太赫兹时域光谱系统中飞秒激光脉冲的色散特性,通过理论分析建立了角色散与时域色散的数学模型,并采用光线追迹法数值模拟了在三种不同的光栅常数下光栅对间距和系统光路入射角对其色散补偿效果的影响。结果表明:在给定光栅常数的情况下,系统的色散随光栅对间距的增大而增大;不同光栅常数下色散量随入射角的变化趋势不同,但总体色散量随光栅常数的增大呈上升趋势。从间距和入射角两方面验证了选取光栅常数为1200 mm^(-1)的光栅的合理性。最终,通过实验证明了光栅对的脉冲压缩效果满足太赫兹时域光谱系统对脉冲压缩的要求。In order to solve the problem of low pumping efficiency of terahertz wave due to the dispersion effect of femtosecond laser pulse transmission in optical fiber,aiming at the dispersion characteristics of femtosecond laser pulse in terahertz time-domain spectrum system,the mathematical models of angular dispersion and time-domain dispersion are established through theoretical analysis.The effects of grating pair spacing and incident angle of system optical path on dispersion compensation are numerically simulated by ray tracing method under three different grating constants.The results show that the dispersion of the system increases with the raise of grating pair spacing when the grating constant is given.When different grating constants are selected,the variation trend of dispersion is different with the change of incident angle,but the total dispersion increases with the increase of grating constant.The rationality of selecting a grating with a grating constant of 1200 mm^(-1)is verified from the two aspects of spacing and incident angle.Finally,the pulse compression effect of the grating pair is proved by experiments,which meets the pulse compression requirements of terahertz time-domain spectroscopy system.

关 键 词：光栅 脉冲压缩 色散补偿 光栅对 光线追迹 太赫兹 

分 类 号：O436[机械工程—光学工程]