THz成像技術之研究

Abstract

在本論文中，我們架設了一個含有快速掃描的THz Imaging 系統 並介紹THz 成像方式以及快速掃描，成像方式有固定時間延遲、不 同時間延遲成像、頻域振幅成像、以及頻域相位成像，我們並且掃描 了新台幣之浮水印及火柴盒。其快速掃描系統能達到以33 秒鐘得到 訊噪比131，兩分鐘半達到212，十四分鐘達到436，最快掃描速度 為以鎖相放大器放大器時間常數1ms 掃描頻率為3Hz。我們也初步對 系統的解析度做分析，量取焦點之THz 焦點大小，並改用小gap 之 天線來做Imaging，其解析度約可達到400µm。

We constructed a THz Imaging system with fast scan, and introduce THz imaging and fastscan. Our means of Imaging include fixed time delay, different time delay, amplitude at different frequency, and phase at different frequency. We also scanned currency mark on New Taiwan Dollars and a match box. It can achieved a SNR of 131 in 33 seconds, 212 in two and half minutes, 436 in 14 minutes. The fastest scan rate is 3Hz with 1ms of LIA time constant. We also simply discuss the resolution of our system, measured the THz spot size at focal point, and used a small gap antenna to do imaging to improve its spatial resolution. Its resolution may achieve about 400µm now.