双焦点太赫兹主动成像系统的扫描轨迹  

Scanning Track of an Active Bifocal Terahertz Imaging System

作　　者：李志鹏 王慧[1] 周德亮[1,3] 王岩 苏润丰 李绍和 涂学凑 陈健[1,2] 吴培亨 Li Zhipeng;Wang Hui;Zhou Deliang;Wang Yan;Su Runfeng;Li Shaohe;Tu Xuecou;Chen Jian;Wu Peiheng(Research Institute of Superconductor Electronics,Nanjing University,Nanjing 210023,Jiangsu,China;Purple Mountain Laboratory,Nanjing 211111,Jiangsu,China;Jiangsu Hengtong Terahertz Technology Inc.,Shanghai 200120,China)

机构地区：[1]南京大学超导电子学研究所,江苏南京210023 [2]网络通信与安全紫金山实验室,江苏南京211111 [3]江苏亨通太赫兹技术有限公司,上海200120

出　　处：《激光与光电子学进展》2023年第12期273-277,共5页Laser & Optoelectronics Progress

摘　　要：在自行搭建的双焦点太赫兹主动成像系统基础上,建立了与角度相关的拟合函数,并利用最小二乘拟合多项式的方法对拟合系数进行计算,成功将扫描轨迹的几何光学追迹计算过程简化成为二元函数计算。该系统为收发同路式像方旋转镜扫描。由于拟合自变量对太赫兹图像的影响很大,采用两种不同的拟合自变量进行计算,并且通过数值分析和成像结果分析比较两者的优劣。实验结果表明,当以旋转镜法向量的坐标分量作为拟合自变量时,计算扫描轨迹的速度减小至3 s/frame,且太赫兹图像非常准确。该系统实现了在约8 m处,50 cm×100 cm视场内达3 cm空间分辨率的快速精确成像。这为扫描式太赫兹快速成像系统提供了有价值的参考,对实时太赫兹安检、无损检测等领域有着实用意义。In this study,an angle-related fitting function wherein the fitting coefficient is calculated using the least square fitting polynomial method is established for an active self-built dual-focus terahertz imaging system.In addition,the geometric optical tracking calculation process for the scanning track is successfully simplified into a binary function.The system adopts the same channel image scanning technique using a rotating mirror.Because the fitting independent variable has a significant influence on the terahertz image,two different fitting independent variables are used for calculation,and the advantages and disadvantages of the two are compared through numerical and imaging results analyses.The experimental results show that when the coordinate component of the normal vector of the rotating mirror is used as the fitting independent variable,the calculation time of the scanning trajectory is reduced to 3 s/frame,and the terahertz image is very accurate.Moreover,the system realizes fast and accurate imaging under a spatial resolution of 3 cm and view field of 50 cm×100 cm when placed at a distance of approximately 8 m.Thus,this study provides a valuable reference for quick scanning in terahertz imaging systems and is of practical significance for real-time terahertz security inspection and non-destructive testing.

关 键 词：成像系统 太赫兹主动成像 最小二乘拟合多项式法 拟合轨迹 快速成像 

分 类 号：O436[机械工程—光学工程]