Nonlinear Sagnac fiber interferometer based on coherent feedback control
Xiaoyu Feng, Min Nie, Guang Yang
In order to improve the phase sensitivity of nonlinear Sagnac interferometer, a nonlinear Sagnac fiber optic interferometer based on feedback control is designed to improve the phase sensitivity by introducing a feedback control loop into the nonlinear Sagnac interferometer. This design adopts the composite feedback control structure of Nonlinear Beam Splitter (NBS) and Linear Beam Splitter (BS). By adjusting the reflectivity of the Linear Beam Splitter, the intensity of the feedback signal can be effectively changed to regulate the phase sensitivity of the interferometer. The feedback amplified signal light passes through the Sagnac fiber optic ring before being processed by a second NBS for quantum enhancement to further improve the phase sensitivity of the interferometer. The simulation results show that the phase sensitivity of the interferometer with certain feedback strength is better than that without feedback. Especially when the phase difference is π, the phase sensitivity of the interferometer with low and medium feedback strengths is improved by 33.3% and 28.9% respectively; In addition, the gain coefficient of the NBS is a key parameter affecting the performance of the interferometer, and a suitable gain coefficient can further optimize the phase sensitivity of the interferometer.
International Conference on Optoelectronic Information and Optical Engineering (OIOE)•Jun 10, 2025•0 citations