基于曲线反射面快速扫描光学延迟线设计

Design of Fast Scanning Optical Delay Line Based on Curved Reflecting Surface

太赫兹时域光谱系统作为有效的相干探测技术,提高太赫兹的探测速度是其研究重点。通过说明延迟线的基本原理并进行数学分析,设计了具有4个子叶片的快速旋转延迟线,总延迟距离为127.339 mm,延迟时间为424.464 ps。利用LIGHTOOLS进行理论光线模拟,对轴振动和安装产生的误差进行模拟,并对轴体旋转的模态进行分析。设计和仿真结果表明:此光学延迟线装置能在空间上有效地分开光束平行出入射,且低于一阶模态频率,可稳定旋转,加工可行性较高,能实现较大的延迟时间且重复性较好,有利于快速探测到太赫兹信号,提高太赫兹时域光谱系统扫描速度。

THz time-domain spectroscopy system is an effective coherent detection technology;and improving the detection speed of THz is the focus of its research.By elaborating the basic principle of the delay line and performing mathematical analysis,a fast-rotating delay line with 4 sub-blades is designed.The total delay distance is 127.339 mm and the delay time is 424.464 ps.Theoretical light simulation is performed by utilizing LIGHTOOLS;the shaft vibration and installation errors are simulated;and the mode of shaft rotation is analyzed.The design and simulation results show that the optical delay line device can effectively separate the beams in space and the incident and exit lights are parallel.It can rotate stably below the first-order modal frequency and the feasibility of processing is high.The device can achieve a larger delay time and good repeatability,which is beneficial to quickly detect the terahertz signal and improve the scanning speed of the terahertz time-domain spectroscopy system.