Study on measurement technology of stray light signal in space optical imaging system

With the increasing demand of space optical imaging system for detecting dim targets, the level of stray light suppression limits the further improvement of detection perfounance of the optical system. In this paper, PST (Point Source Transmittance) method is used to build a set of large aperture and high precision measuring device. The device adopts visible light and near-infrared light sources. Collimation is carried out through the parallel light tubes and irradiation is carried out on the calibration lens in the double cylindrical chamber. The irradiance of the measured system under different off-axis angles (+/- 5 degrees -+/- 60 degrees) is measured. The measured value curve of PST was drawn and compared with the designed value curve, which are basically consistent. Furtheimore, the measurement range of the system reaches 10(-3) -10(-10), which meets the engineering needs of stray light measurement of space optical system.