Single-mode fiber auto-coupling system with wedges

Abstract Efficiently coupling Gaussian beams into single-mode fibers (SMF) plays an important role in scientific experiments. However, the optical misalignment will decrease the coupling efficiency dramatically. In this paper, we proposed and investigated a SMF auto-coupling system consisting of two wedges driven by stepper motors. We simulated and analysed the dual-wedge system’s ability of correcting optical misalignment and experimentally demonstrated the feasibility of this proposal. The results show that when the optical path is misaligned within a certain range, by automatically rotating the two wedges, the system can restore the efficiency to near the manually optimal coupling efficiency. The system inherits the stability of the stepper motors and will be beneficial for space applications and other unmanned scientific experiments.