拉锥光纤长周期光栅模式分裂与折射率特性

Refractive index characteristics and mode splitting of long-period fiber gratings written in the tapered fiber

仿真研究了拉锥光纤长周期光栅的传输特性,发现长周期光纤光栅的同一阶包层模分布曲线在光纤锥区直径为55~110μm时会发生分裂,且分裂后的光栅谐振峰对于外界折射率的灵敏特性有较大差别.

Transmission characteristics of long-period fiber gratings （LPFGs） written in a tapered fiber is investigated by numerical simulation. It has been found that splitting of the mode distribution curve happens for the same order cladding mode of LPFG when the thinnest diameter of the tapered fiber is between 55 μm and 110 μm. The two resonance dips correspond to splitting from the same order cladding mode show different refractive index characteristics.