Path analysis and suppression of self-generated thermal emission in infrared optical systems

In this paper, simulation model of infrared optical systems with Cassegrain structure has been built up, and the stray radiation analysis has been performed. The contributions of each component to stray radiation of infrared system and the corresponding optical path of stray radiation have been studied in detail. On this basis, the flux distributions of the stray radiation of the major contributors on the detector have been simulated, and the uniformity of the flux distributions has also been discussed. In order to suppress the stray radiation of the system, the corresponding methods have been adopted according to different paths of the stray radiation. Finally, the flux of stray radiation and the uniformity of the flux distributions on the detector before and after taking the suppression measures have been compared and analyzed. The results indicate that the methods for suppressing the stray radiation according to the characteristics of stray radiation source can effectively improve the stray radiation performance of the system, resulting in the improvement of the detection performance of the system.