一种应用于太赫兹成像的准光学系统设计

Design of a quasi optical system applied to terahertz imaging

利用太赫兹近感成像技术为人体安检提供一种高效的方法,设计一种应用于被动太赫兹近感成像的准光学系统,此成像系统主要用于对人体成像,检测人体携带的危险隐匿物。准光学系统由介质透镜、馈源天线阵、扫描镜组成,透镜为凸透镜,透镜表面采用非球面,材料为高密度聚乙烯,通过物理光学法,计算介质透镜天线近场,并分析其物像关系,使其满足大视场、高分辨率等指标要求。系统成像结果表明,设计的太赫兹准光学系统视场范围达到900mm×2 000mm,在距离3m的物方能分辨尺寸为30mm的物体。

In order to provide an efficient means for human security inspection by using the terahertz near field imaging technology,aquasi optical system applied to passive terahertz imaging systems is designed and this imaging system is mainly applied to human body imaging and detecting dangerous concealment carried by human.The quasi optical system is composed of dielectric aspheric biconvex lens,antenna array,scanning mirror and the aspheric biconvex lens is made of high density polyethylene.Using physical optics method to calculate the near field of dielectric lens antenna and the relationship between the object and the image is analyzed so that it can meet the requirement of large field and high spatial resolution.The system imaging results show that the designed terahertz quasi optical system gets the target field of 900 mm×2 000 mm and can distinguish the objects of 30 mm size with the distance of 3 m.