高非线性光子晶体光纤中布拉格光栅的制作

采用相位掩模版法实验研究了高非线性掺锗光子晶体光纤中布拉格光栅的制作。实验中采用的光子晶体光纤的非线性系数约为12 W^－1km^－1,模场直径约为2.4 mm。 分析了布拉格光栅的反射率随着曝光脉冲数的变化,随着曝光脉冲数的增加其反射率逐渐达到饱和,继续增加曝光量发射率开始下降。实验验证了可以在高非线性光子晶体中写入布拉格光栅,得到光栅的反射率为44.4%,这对于研究光纤布拉格光栅的非线性效应和应用具有重要意义。讨论了影响布拉格光栅写入效率的因素。

Fabrication of Bragg grating in a highly nonlinear photonic crystal fiber

Fabrication of the Bragg grating in a highly nonlinear photonic crystal fiber was investigated experimentally by phase mask method. Nonlinear coefficient and mode-area diameter of the highly nonlinear photonic crystal fiber are 12 W^-1km^-1 and 2.4 mm respectively. The evolution of reflectivity of the Bragg grating against irradiation pulse number was analyzed. The reflectivity entered into a saturated phase with increasing the irradiation pulse number, and it began to decrease with further increasing exposure. Bragg grating with the reflectivity of 44.4 % in the highly nonlinear photonic crystal fiber was demonstrated, which paved the way for studying the nonlinear effects of fiber Bragg grating and their applications. The factors affecting writing efficiency Bragg grating in the highly nonlinear fiber were discussed.