以啁啾光纤光栅为补偿器的自适应PMD补偿的实验研究

The Experimental Study of Polarization Mode Dispersion Compensation Using Chirped Fiber Grating as Compensator

基于光信号偏振度(DOP)与光纤链路差分群时延(DGD)良好单调关系,提取光信号的DOP作为监测信号,通过搜索运算控制偏振模色散(PMD)补偿器,找到链路中DOP达到最大值时补偿器的状态,从而实现一阶PMD的补偿.采用等效啁啾技术,用具有光敏性质的保偏光纤制成啁啾光纤光栅,将其作为PMD补偿器中的时延线,完成了10Gbit/s、NRZ码光纤通信系统的自适应PMD补偿的实验研究.在自适应PMD补偿的控制算法中,使用了粒子群最优化(PSO)的人工智能搜索法,它具有快速搜索到全局最大值、不易陷入局部极大、抗噪声等特点.实验结果显示,以双折射啁啾光纤光栅为补偿器的自适应PMD补偿系统具有良好的补偿效果.

Based on the good relation of degree of polarization (DOP) of feed-back signals and differential group delay (DGD), DOP was extracted as monitor signal to find out the maximum DOP of fiber link with the aid of controlling algorithm to control compensators to obtain optimal compensation. Chirped fiber grating made of photosensitive polarization maintaining fiber was fabricated through the equivalent chirp technology, which was used as time delay line of PMD compensator. The experimental study of adaptive polarization mode dispersion (PMD) compensation in the 10 Gbit/s nonreturn-to-zero(NRZ) transmission system was reported. Meanwhile, a particle swarm optimization (PSO) technique into automatic PMD compensation was used. PSO has the characteristics of converging for global optimum rapidly and avoiding for being trapped into local sub-optima and robust to noise. The experiments show that the adaptive PMD compensation system on which chirped fiber gratings are used as compensators woks very well.