建立了一套透射式逐点扫描太赫兹(THz)辐射成像装置,它采用〈100〉-InAs晶体作为高功率、宽频谱的THz辐射源和高灵敏度、低噪声的电光取样差分探测方法,具有对隐蔽在非透明电介质材料内物体成像的能力.并且,系统能够获得成像物体上每一点的光谱数据,可以对物体进行光谱成像.利用多种基于傅立叶变换的数据处理方法给出了葵花籽样品的透射图像,并对其中的几种进行分析和对比.全面介绍透射式逐点扫描THz成像的关键技术,包括成像装置、光束测量、数据处理和分析等几个方面,对有效利用THz成像技术和开展THz成像领域的相关研究具有指导意义.
A transmitted scanning terahertz imaging system, which has the 〈100〉-InAs emitter of high power, wide frequency spectrum and the detector of high sensitivity and low noise, is presented. It owns the capacity of detecting something that has been shielded by some opaque dielectric materials. Moreover, spectroscopy data at each point of the sample can be acquired by using this system. Using these data the spectroscopy images can be rebuilt. Lots of THz images of sunflower seed sample by using various data processing methods based on the Fourier transform spectroscopy are given and compared. In addition, the several important factors of the sustem, including setup, measure to the beam, data processing described in detail, which are very essential to further research and application.