有源光纤自相位调制再生器的磁控特性

Magnetically controllable properties of active fiber regenerators based on self-phase modulation

利用有源非线性光纤的磁光效应可实现智能的光纤信息处理,完成光信号的同时放大和整形。根据导波光脉冲的磁光非线性耦合模方程,采用分步傅里叶算法计算了增益分布对自相位调制频谱展宽的影响,计算结果与Opti System仿真一致。研究表明,基于自相位调制的再生器输入饱和功率随增益泵浦功率、光纤长度以及铒离子浓度的适当增加而减小,从而提高再生器的饱和增益。在有源非线性光纤轴向施加磁场,可提高再生器输入"传号"光脉冲的幅度抖动容限,还可以通过调节磁场改变自相位调制频谱展宽的大小,使再生器的功率转移函数与输入劣化信号特性灵活匹配。

Active nonlinear fibers with magneto-optical effects are useful for intelligent fiber information processing, especially the realization of both amplifying and reshaping functions. According to the magneto-optical nonlinear coupled-mode equations for guided optical pulses, the influence of power gain distribution on self-phase-modulation （SPM）-induced spectrum broadening is calculated by using the split-step Fourier method and the calculation results are in good agreement with the OptiSystem simulations. The saturation input power of the SPM-based regenerators is reduced with the increase of gain pump power, fiber length, or erbium ion density, and then leads to the improvement of the saturation gain. Under the applied magnetic field along the axis of the active fibers, the resulting regenerators have a larger tolerance to the amplitude fluctuation for input mark pulses, and the power transfer function of regenerators can flexibly match with the input degraded signals due to the magnetic control mechanism of SPM-induced spectrum broadening.