Double triangular prism filter based on the optical-readout method in a microelectromechanical infrared imaging system

This paper presents a novel filtering method with a double triangular prism in an optical-readout thermal imaging system. First, the working principle of this system is described in detail, followed by the analysis of sensitivity. Then, infrared images of hands are obtained. On the basis of the analysis, it is concluded that this filtering method, whose noise equivalent temperature difference (NETD) can reach 145 mK, is effective in obtaining high-quality images. Finally, comparing the filtering method with a knife-edge filter, we can draw the conclusion that the filtering method can effectively improve image quality (the value of NETD is less than that of a knife-edge filter).