An approach to remove the background light based on linearly polarized light in the inter-satellite optical communications

In the inter-satellite optical communications, background light is an important factor that worsens the acquisition performance and tracking precision of the system. In general, optical filters are applied in eliminating background light. But the bandwidth of the optical filter is a bottleneck for improving the performance of the optical system further. We propose a new method for decreasing background light, in which linearly polarized light is employed as the beacon light. The theoretical model of acquisition probability is derived. Contrastive analysis is performed, among the system with the pure optical filter, the system using the linearly polarized light and the system with the circularly polarized light. Numerical simulations and experimental verification lead to the conclusion that acquisition probability of the system with linearly polarized light is greater than that of the other systems, and this approach is effective. This work can benefit the design of inter-satellite optical communication system.