太赫兹成像系统的分析与控制

太赫兹波能穿透许多物质,相对于可见光和X射线,其具有非常强的互补特征;它的光子能量极低,且没有X射线的电离性质,因此太赫兹成像技术的应用前景非常广阔。在太赫兹成像系统中,系统参数的合理选择,软件部分的合适控制,对系统的成像结果有着至关重要的作用。从调试过程中得到的图像来看,不合适的处理如斩波器、锁相放大器参数选择不当等,将会导致两行之间错位、信噪比不高,以至于图像失真,甚至无法辨认。对出现这种错位现象的原因进行了研究,在硬件参数选择和软件两个层次,对导致该现象的系统偏差进行控制、补偿和消除,最后给出成像结果。扫描成像结果表明,搭建了稳定合适的光路,选择了适当的仪器参数,在软件上控制了偏差,通过实验和测试,系统达到了较好的成像效果。

Analysis and Control of Terahertz Imaging System

Terahertz wave can penetrate many materials and has a very strong complementary characteristic compared with visible light and X-ray,whose photon has very low energy,and does not have ionization characteristic of X-ray,so Terahertz imaging technology has a broad application prospect.The system referred in the paper consists of Terahertz radiation source FIRL100 laser,Terahertz detecting instrument golay cell detector,stepper motor controller and translation stage,lock-in amplifier SR830 and chopper and so o...