摘要

A novel polarization control method based on chaotic particle swarm optimization algorithm (CPSO) in distributed fiber-optic vibration sensor is proposed to improve the sensor's positioning accuracy efficiently. The distributed fiber-optic vibration sensor is based on dual Mach-Zehnder interferometer (DMZI) architecture. The DMZI sensor is subject to polarization-induced phase shift (PIS) and polarization-induced fading (PIF) which affects the positioning accuracy of the sensor when constructed using low-birefringence single-mode optical fiber. In order to improve the sensor's positioning accuracy, we proposed a polarization control system based on CPSO which runs automatically and only one polarization controller is used in the interference arm. Because of the character of easy implementation, quick convergence and global search of CPSO, the polarization control method using CPSO as the search algorithm of polarization control is high-efficiency. An experiment according to CPSO was carried out to illustrate the process of polarization control. It has been experimentally demonstrated that the polarization control method can overcome the effect of polarization-induced phase shift and polarization-induced fading and improve the sensor's positioning accuracy efficiently.