光纤Bragg光栅非线性开关动态特性研究

基于光纤Bragg光栅中脉冲演变遵循的非线性耦合模方程，数值分析了光纤Bragg光栅在禁带附近由非线性光学特性导致的Bragg波长偏移。仿真结果表明：随着输入信号功率的增大，光栅的布拉格波长向长波方向移动，反射峰值下降，反射带宽变窄。进一步研究了基于此效应的全光自开关特性，结果表明：此开关的稳定时间短，并且输出脉冲形状保持良好。因此，这种具有高非线性系数的光纤光栅实现的全光开关在全光信号处理方面具有广泛的应用前景。

Dynamic characteristics of FBG nonlinear switch

Based on the nonlinear coupled mode equation governing the pulse evolution in fiber Bragg gratings (FBG), the Bragg wavelength shift near the forbidden band caused by nonlinear optical characteristics was analyzed numerically. A simulation model was established to study the switching performance of FBG for different input powers. The simulation result shows that the Bragg wavelength of the grating moves to longer wavelength, the reflection peak decreases and the bandwidth becomes narrow when the input signal power increases. The characteristics of the all-optical switch based on this effect were investigated. And it shows that the stabilization period of the switch is short and the pulse wave-shape remains undistorted.