FBG的衍射光学特性和耦合模理论分析

Analysis on optical characteristics and coupled-mode theory for fiber Bragg gratings

从衍射光学的角度出发研究了光纤布喇格光栅（ Ｆ Ｂ Ｇ） 的光学特性，进而采用理想模展开的耦合模理论对光纤布喇格光栅的模场分布进行了详细分析，推导出反射率、布喇格反射波长及反射主峰带宽等特性参数的表达式。计算结果表明，理论与实验结果吻合较好。

Optical characteristics of the fiber Bragg grating (FBG) are given based on diffraction optics.By using ideal mode approximation of coupled-mode theory,the mode field of FBG is analyzed in detail,and expressions of such parameters as the reflectivity, the Bragg reflective wavelength and the bandwidth of the maximum reflectivity are derived.The calculation shows that the experimental results closely agree with the theory,which demonstrate the accuracy of the theory.