论文部分内容阅读
将光纤布拉格光栅近似为一维光子晶体 ,研究光栅的能带结构和光学传输特性。利用平面波展开法对光子晶体进行理论研究 ,将研究方法移植到光纤布拉格光栅上 ,并对其进行数值分析 ,得到光栅的传输特性。研究表明 ,光栅反射谱有多个反射峰 ,峰值中心频率是基频的整数倍 ,而且峰值处存在光子带隙 ,反射峰带宽对应光子带隙宽度 ,中心频率和带宽随光栅长度、高介电常量材料占空比、调制深度而变化。结果与传统的耦合模理论一致。
The fiber Bragg grating is approximated as a one-dimensional photonic crystal, and the energy band structure and optical transmission properties of the grating are studied. The theory of photonic crystal was studied by the plane wave expansion method. The research method was transplanted to fiber Bragg grating and the numerical analysis was carried out to obtain the transmission characteristics of the grating. The results show that there are many reflection peaks in the grating reflection spectrum, the center frequency of the peak is an integral multiple of the fundamental frequency, and there is a photonic band gap at the peak. The reflection peak bandwidth corresponds to the photonic band gap width. The center frequency and bandwidth vary with the grating length, Constant material duty cycle, modulation depth changes. The result is consistent with the traditional coupled-mode theory.