摘要
对折射率剖面非均匀的少模光纤Bragg光栅(FMFBG)的反射特性进行了数值仿真。用shooting法数值求解了耦合模方程,得到了FMFBG中线偏振模的反射谱。当不考虑光敏特性的饱和效应,且光纤芯对紫外光的吸收系数不变时,仿真结果表明,光纤纤芯对紫外光的吸收导致折射率变化横截面分布的不均匀,在不考虑饱和长度的情况下,模式间的互耦合峰总是存在的。线偏振模间的互耦合峰反射率随纤芯边界最大光致折射率变化的增大而呈二次形增长,LP01模、LP11模自耦合峰反射率也分别呈近似六次和四次多项式形增大。
The reflection characteristics of the few-mode fiber Bragg gratings （FM-FBG） , which have nonuniform transverse profile of refractive index change, are simulated numerically. Coupling mode functions are solved numerically using the shooting method to obtain reflection spectrums of the FM-FBG. When the saturation effect of photosensitivity is not considered and the UV-absorption coefficient of fiber core is constant, the results of simulation reveal that when the saturation length is not considered, the non-uniform transverse profile of refractive index change induced by the UV-absorption of the fiber core makes the cross-coupling reflection peak exist always. The maximum index change at the core-cladding interface increases while the cross-coupling reflection peaks of Linear-polarized modes change quadratically. And the self-coupling reflection peaks LP01 of LP11 mode and mode increase as almost six-square polynomial and biquadratic respectively.
出处
《电子器件》
EI
CAS
2006年第1期114-117,共4页
Chinese Journal of Electron Devices
