Self-Mixing Interference in Fiber Ring Laser With Parallel Dual-Channel

A new approach for self-mixing interference in fiber ring laser with a parallel dual-channel is presented. The output power of the dual-channel with optical feedback is theoretically deduced and simulated based on the transcendental equation of fiber ring laser. The output variation and modes competition between the two channels in a fiber laser is also analyzed. We demonstrate this system to measure the movement of two targets, and discuss the influence on self-mixing interference under the different feedback conditions. The experimental results show a good agreement with the simulation, and indicate that the self-mixing interference with parallel dual-channel is an efficient approach for multiple displacement measurement.