论文部分内容阅读
为了研究布拉格光纤的模式特征和传输特性,提出了超格子模型,利用傅里叶级数表示光纤横向折射率分布,利用平面波展开法分析布拉格光纤的能带结构,基于厄米-主斯函数的局域正交函数展开法,从全矢量耦合波动方程出发,得到关于模式传播常量和电场展开系数的本征方程,从而分析布拉格光纤的模式特征。以高折射率芯布拉格光纤为例,实现了该算法,得到基模与二次模的横向电场分布、基模色散曲线和模式双折射。基模的模式双折射可用于衡量算法的精度,结果表明该算法精度较高。超格子模型不仅可以用于研究高折射率芯布拉格光纤,而且同样可以研究低折射率区域导光的布拉格光纤。
In order to study the mode and transmission characteristics of Bragg fiber, a super lattice model is proposed. The Fourier transform is used to describe the fiber lateral refractive index distribution. The plane wave expansion method is used to analyze the band structure of Bragg fiber. Based on Hermite - Based on the full-vector coupled wave equation, the eigenvalue equation of mode propagation constant and electric field expansion coefficient is obtained, and the mode characteristics of Bragg fiber are analyzed. Taking high-index fiber Bragg fiber as an example, this algorithm is realized, and the transverse electric field distribution, fundamental mode dispersion curve and mode birefringence of the fundamental mode and the second mode are obtained. The fundamental mode birefringence can be used to measure the accuracy of the algorithm. The results show that the algorithm is more accurate. The super lattice model can be used not only to study high-index core Bragg fibers, but also to study Bragg fibers with low refractive index regions.