A Bidirectional Multi-Format/Rate-Adjustable Integrated Laser Communication System for Satellite Communication

Satellite optical communication networks have become a promising core network structure, surpassing 5G and 6G, and are expected to realize seamless connections between terrestrial and non-terrestrial networks. Constructing an optical satellite network that can achieve various link schemes and enable bidirectional communication with multiple optical satellites at a low cost (including low power consumption, low weight, and low space occupation for each satellite) poses a technical challenge. In this paper, we propose and establish a multi-format/rate-tunable integrated laser communications hardware platform that can switch between different links by controlling the modulation format and rate. The platform supports OOK, QPSK, and BPSK modulation with rates ranging from 0.625 to 10 Gbps. Experimental demonstration of bidirectional communication is conducted over a free-space optical link. At a distance of 510 meters, sensitivity tests are conducted for signals with various modulation formats and rates. The receiving sensitivity at the 3.8e-3 FEC threshold is -46 dBm for 10 Gbps PDM-QPSK signal, and is -58 dBm for 625 Mbps BPSK signal. Results show excellent signal sensitivity across different formats and rates. Additionally, the platform is capable of performing ranging while communicating with a minimal ranging error of 2.9% of the width of a code word.