Design and Simulation of the Baffle of Low Light Level Imaging Sensor

Low light level imaging sensor is used to detect faint visible light, such as the moonlight, starlight, airglow and so on. The sensor has had great development with its high sensitivity, large dynamic range, therefore, stray light can cause imaging failure directly. A two-class truncated cylinder baffle was proposed and baffle design method is discussed in detail. The point source transmittance(PST) is used to evaluate the stray light suppression of the system. The system is used in field bias to avoid ghost in transmission optical system. In the end, the simulation results are analyzed and calculated with Lighttools software. Finally the PST curves were given at the off-axis angles between 18°and 40°. The analysis results show that the two-class truncated cylinder baffle could stop the stray light from the veiling glare rejection angle and reduce the scattered rays reflected by the baffle. For stray light sources with small off-axis angles, the PST is reduced to the order of −7. It is capable of meeting usage requirements.