Xi'an Institute Of Optical Mechanics, Chinese Academy Of Sciences (XIOE, CAS) Makes Progress in Space Laser Communication Capture And Chain Building Research

Recently, the Key Laboratory of Space Precision Measurement Technology (KLSPMT) of the Chinese Academy of Sciences (CAS) has made new progress in space laser communication acquisition and chain building and successfully completed in-orbit validation, and the related research results have been published in November 2023 under the title of "On-orbit Space Optical Communication Demonstration with 22s Acquisition Time". The research results were published in November 2023 in Optics Letters, a journal of the Optical Society of America, under the title of On-orbit Space Optical Communication Demonstration with 22s Acquisition Time. The paper's co-first authors are Xuan Wang and Junfeng Han, special research assistants in the Optoelectronic Tracking Laboratory, and the corresponding author is Zhiyuan Chang.
Space laser link networking is the basic condition for realizing space laser communication, how to quickly and stably capture and build the link in a short time is the key to the success of networking, so the realization of fast, wide-range beam capture and stable high-bandwidth, high-precision beam tracking has become the core technology hotspot. In general, the laser communication terminal usually needs to spend a lot of time to complete the coaxiality in-orbit calibration work at the early stage of entering the orbit. The attitude determination error of the satellite platform, orbital error, structural deformation triggered by environmental changes and other reasons will lead to a large uncertainty field (FOU), coupled with dozens of micro-arcs of the beam divergence angle, all these factors will make the in-orbit laser capture become extremely tricky.

Fig. 1 Schematic diagram of interplanetary laser communication test in the same orbit
In order to complete the in-orbit laser communication link capture faster, the research team proposes a fast optimization method in orbit using the installation matrix parameters of the laser communication terminal star sensitizer. This method can effectively reduce the error of the installation position of the optical axis and precision adjustment mechanism of the laser communication terminal due to the stress release of the satellite into orbit. By skillfully correcting the installation matrix parameters, the initial pointing accuracy of the laser communication terminal can be greatly improved and the range of uncertainty field can be reduced, so as to improve the capture probability of the laser communication terminal scanning in orbit and reduce the capture time.

Fig. 2 Experimental results of in-orbit capture and chain construction
This research work is based on a lot of theoretical accumulation and on-orbit experimental research by the research team of the Optoelectronic Tracking Laboratory, which is supported by the Key Deployment Program of the Chinese Academy of Sciences (CAS) and the National Natural Science Foundation of China (NSFC).