快速旋转光学延迟线的非线性误差校准技术  

Nonlinear Error Calibration Technique for Fast Rotating Optical Delay Lines

作　　者：祝莉莉 薛竣文 任姣姣[1,2,3] 张丹丹 顾健[1,2,3] 张霁旸 李丽娟 Zhu Lili;Xue Junwen;Ren Jiaojiao;Zhang Dandan;Gu Jian;Zhang Jiyang;Li Lijuan(School of Optoelectronic Engineering,Changchun University of Science and Technology,Changchun 130022,Jilin,China;Key Laboratory of Optical Control and Optical Information Transmission Technology,Ministry of Education,School of Optoelectronic Engineering,Changchun University of Science and Technology,Changchun 130022,Jilin,China;Zhongshan Institute of Changchun University of Science and Technology,Zhongshan 528403,Guangdong,China)

机构地区：[1]长春理工大学光电工程学院,吉林长春130022 [2]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 [3]长春理工大学中山研究院,广东中山528403

出　　处：《光学学报》2024年第5期93-100,共8页Acta Optica Sinica

基　　金：吉林省科技发展计划项目(20220508032RC);中山市第九批创新科研团队(GXTD2022010);中山市第二批社会公益和基础研究项目(2022B2012)。

摘　　要：光学延迟线是影响太赫兹时域光谱系统中太赫兹信号准确性、信噪比以及频谱分辨率的关键环节。本文设计了一种由24个转盘反射面(TRS)构成的快速旋转光学延迟线(FRODL)。通过对FRODL工作角度的仿真,得到了其理论延迟时间和理论非线性度。基于FRODL实际耦合过程中耦合功率的波动性大小,确定了FRODL的实际工作区间,并搭建了偏振迈克耳孙干涉系统,对FRODL结构的实际延迟时间进行标定,得到了各转盘反射面工作的实际延迟时间。标定结果显示,FRODL校准前的最大非线性误差为0.094 ps,非线性度为0.215%。通过两次利用三次样条插值,对FRODL实际延迟时间和采样点信号进行匹配,获得了校准后的太赫兹等间隔时域波形。Objective As devices can change the relative delay time of reference light and detection light in optical detection systems,optical delay line(ODL)is widely employed in terahertz time-domain spectroscopy(THz-TDS),optical coherence tomography,ultrafast time resolution spectroscopy,and pump-probe technique.In particular,ODL is adopted to scan and detect THz-TDS signals by changing the relative delay of femtosecond and terahertz(THz)pulses in THzTDS.As such,ODL is a key component that affects the accuracy,signal-to-noise ratio,and spectral resolution of THz signals.In the THz-TDS system,the ODL nonlinearity directly affects the accuracy and consistency of the sampling signal of the THz-TDS system.The nonlinear delay time change leads to the nonlinear actual sampling interval of the system,which brings the nonlinear change in the optical path of the femtosecond laser pulses(FLP)and thus causes the line position error of the THz spectrum.The greater nonlinear error of the THz sampling signal results in more severe distortion of the collected THz signals and greater difficulty in subsequent data processing.Therefore,it is urgent to solve the nonlinear problem of various rotating optical delay line(RODL)delay time.We design a fast rotating optical delay line(FRODL)composed of multiple turntable reflection surfaces(TRSs)and construct a polarized Michelson interference system.Based on the actual calibration results of the total delay time and delay time interval of the FRODL structure,nonlinear error calibration of the actual delay time of FRODL is achieved.Methods We first design a FRODL composed of multiple TRSs and analyze the structure and working principle of FRODL.Then,the feasibility of the FRODL optical path is further verified,and the optical path structure of FRODL at different rotation angles is simulated to obtain the theoretical working angle of FRODL.Combined with the theoretical mathematical model of FRODL,the theoretical delay time of FRODL is obtained,and the theoretical nonlinearity is fitted using the l

关 键 词：光学延迟线 非线性校准 太赫兹时域光谱系统 延迟时间 非线性误差 

分 类 号：TN247[电子电信—物理电子学]