Fig. 1. (a) Spaceborne lidar receiver optical system and (b) detected energy classification of detector

Fig. 2. Schematic diagram of the source of noise

Fig. 3. (a) Stray light analyzing model and (b) new baffles model in achromatic collimator barrel

Fig. 4. Design method of the new baffles in achromatic collimator barrel

Fig. 5. New designed baffles in achromatic collimator barrel

Fig. 6. Noise light simulation results. (a), (c) and (e) are the scattering ray plots of models 1, 2, 3, respectively; and (b), (d) and (f) are the detector views respectively. There is no stray light to the detectors. (g) is the detector view of telescope mirrors scattering simulation model. Detected noise light power is 1.22 pW. (h) is the detector view of new noise light suppression baffles model. Detected noise light power is 0.00656 pW