基于单个宽频CMOS探测器的太赫兹焦平面扫描成像系统OACSTPCD

Terahertz wave is an electromagnetic wave between millimeter wave and infrared light,which has many feature like strong penetration capability,non-ionization and high instantaneous bandwidth.For these qualities,terahertz waves have a wide range of poten-tial applications in non-destructive testing,medical imaging,safety inspection,and other areas.In the imaging system,the detector is an essential part.This paper presents a structure that combines the output of narrow-band detectors with different center frequencies to re-alize wide-band detection.In order to reduce the area,these narrowband detectors adopt a nested structure,which means that the high-frequency narrowband detectors are placed inside the low-frequency narrowband detectors in turn.Each narrow-band detector includes a loop antenna,a matching network and a field effect transistor(FET)detector circuit.The detector is fabricated in a 65 nm standard CMOS process,and the detection frequency range covers 100 GHz to 1 000 GHz.Based on this broadband detector,we propose a tera-hertz focal plane imaging system,which mainly consists of a terahertz radiation source,a PTFE lens,a broadband CMOS detector,etc.The measurement results have shown that the focal plane imaging system is capable of stably imaging at frequencies of 100 GHz,220 GHz and 300 GHz.The imaging quality improves significantly with increasing frequency.In order to solve the problem of missing infor-mation in measurement images,the morphological closing algorithm is used to process the original image.This algorithm effectively fills in the missing information and enhances the quality of the image.