Spatial Light to Single-Mode Fiber Nutation Coupling Technology

This study describes the spatial light to single-mode fiber coupling principle, designs a nutation coupling algorithm based on a combination of fast mirror and fiber photodetector, and simulates the dynamic tracking process of the fiber end surface using LabVIEW. According to the simulation, the coupling experiments of laser nutation system arc conducted, resulting in a coupling efficiency of 59.63% under static conditions and a video transmission demonstration with 1. 65-GHz code rate. Further, the validity and feasibility of the nutation coupling algorithm arc verified. Based on the experimental and simulation results, the study analyzes the influences of the nutation parameters, including the nutation radius, convergence step length, and number of nutation sampling points, on the coupling performance. The results denote that when the nutation radius increases from 0. 1 mu m. to 2. 5 mu m., the coupling efficiency and stability decrease, whereas the coupling rate does not exhibit a significant change. However, when the nutation radius is considerably small, the convergence angle recognition error will increase, whereas the coupling speed will decrease. When the convergence step increases from 0.1 mu m. to 2.5 mu dm., the coupling efficiency and coupling stability decrease, and the coupling rate increases. When the number of nutation sampling points is reduced from 100 to 5, the coupling efficiency and stability have no obvious change. However, due to too few sampling points, the convergence angle resolution decreases and the coupling rate decreases significantly.