基于二维光子晶体波导的1×5等比分束器

1×5 equal-score beam splitter based on two-dimensional photonic crystal waveguide

在完整的二维正方晶格硅光子晶体中引入点缺陷和线缺陷,利用点缺陷和线缺陷的耦合效应,提出一种基于二维光子晶体的1×5等比分束器。利用平面波展开法和时域有限差分法,对提出的1×5等比分束器进行了研究。研究结果表明,通过合理设置耦合区域的介质柱半径,可使1.55μm入射光实现等比传输到5个输出端口;为提高总透过率,在1×5等比分束器的弯曲波导处增加散射介质柱,并对相关参数进行优化,最终实现99.65%的透过率,附加损耗0.015 dB。该分束器体积较小,结构简单,附加损耗低,在未来的集成光路中具有很好的应用前景。

In this study, point defects and line defects are introduced in a completely two-dimensional square lattice silicon, using the feature of coupling with point defects and line defects, a 1×5 equal-score beam splitter based on the two-dimensional photonic crystal is proposed.The performance of beam splitter is studied by plane-wave-expansion method and finite-difference time-domain method.The research results show that 1.55 μm incident light is transmitted to five port equally can be realized by changing the radius of dielectric column in the coupling region;in order to improve the total transmittance, scattering medium columns were added in the curved waveguide of the 1×5 equal-score beam, and the relevant parameters were optimized.At the same time, the transmittance reaches 99.65% and the insertion loss is 0.015 dB.The beam splitter is characterized by a smaller size, simple structure, low additional loss, which has important application prospect in future integrated optical circuit.