Photoelectric detector surface damage state polarization imaging type detection system

In order to achieve the demand of real-time detector damage detection in the external field, a photoelectric detector surface damage state polarization imaging type detection system was developed. The expressions of the cat eye target echo polarization characteristics (DP) and the degree of polarization (DOP) were derived theoretically, the relationship curves among surface roughness, DOP and DP were simulated by MATLAB software. A simultaneous polarization imaging optical system was designed, a real-time detection outfield experiment of the Charge Coupled Devices (CCD) surface damage state by a 671 nm continuous laser was carried out and a MATLAB GUI-based echo image visualization real-time acquisition system was developed to obtain information such as echo image intensity, DP and spot size. Moreover, by analyzing the morphological images of the damaged and undamaged detector surface with optical digital microscope and white-light interferometer, it was found that the silicon substrate was visible on detector damage surface and the roughness parameter Sq was large. Clearly, the simulation results are in good agreement with the experimental test results. The results show that after the photodetector is damaged, its surface roughness increases, DP decreases, the depolarization characteristic is obvious and DOP decreases. Overall, the polarization imaging technique can effectively detect the damage state of the photodetector surface in real time, and this study provides a good method for real-time detection under external field conditions.