弱光纤布拉格光栅阵列的偏振补偿解调

Demodulation with Polarization Compensation for Weak Fiber Bragg Grating Array

针对弱光纤布拉格光栅阵列的偏振衰落现象,通过理论推导分析了双折射效应诱发的传输脉冲光偏振态变化对干涉光强信号的影响,指出交流项系数耦合是引起零差对称算法解调信号失真的主要原因。为减小该影响,提出了一种基于实时偏振态测量、可消除交流项耦合系数的偏振补偿方法。仿真结果表明,偏振补偿的零差对称算法能在大动态范围内实现稳定的解调输出,有效解决了常规零差对称算法解调过程中出现的信号大范围跳变问题。

To ease the polarization fading phenomenon of weak fiber Bragg grating array,the influence of the polarization variation of the light pulses induced by the birefringence effect on the interference intensity is analyzed theoretically,and the coupling coefficient of the alternating item is found to cause the distortion of phase signal,which is demodulated by the zero difference symmetry algorithm.In order to reduce the impact of the polarization fading phenomenon,we propose a kind of polarization compensation method based on real-time polarization measurement,by which the coupling coefficient of the alternating item is eliminated.The simulation results show that the polarization compensated zero difference symmetry algorithm can achieve stable demodulation results in a large dynamic range,and solve the large-range jump problem of the signals in the demodulation process of the conventional zero difference symmetric algorithm.