在太赫兹成像技术研究中, 分辨率、成像时间和距离是非常关键的参数指标, 为了推动太赫兹成像技术的实用化, 特别是提高对隐藏危险物品的远距离快速预警检测能力, 提出被动式远距离太赫兹快速扫描成像系统。该系统采用单个太赫兹探测器和光机扫描相结合的方式。扫描子系统中, 将六面体转镜置于离轴三反镜系统的平行光路中, 使扫描范围从广泛研究中采用的物空间转换到像空间有效缩小了扫描区域, 缩短了成像时间。本套被动式扫描成像系统主要参数: 探测器频率0.34 THz, 成像距离10 m, 视场±1.5°×±1.5°, 成像分辨率3 cm, 成像时间1 s。

Resolution, imaging time and distance are crucial parameters for terahertz imaging technology. In order to improve the terahertz imaging capability for practical use, especially for quick identification and alarm for hidden objects in a long distance, a passive rapid terahertz scanning imaging system for long distance was presented. In terms of core scanning system, a hexahedral mirror for two-dimensional fast scanning through high speed rotating and reciprocating swing combination was employed. The system was placed in the parallel light path of the off-axis three-mirror system. The scan area focused on image space instead of the object space, which could effectively narrow the scan area, so as to shorten the imaging time. The main parameters of the passive scanning imaging system are as follows: the detector frequency is 0.34 THz, the imaging distance is 10 m, the field of view is ±1.5°×±1.5°, the resolution is 3 cm, and the imaging time is 1 s.