基于自成像多模干涉光子晶体波导的耦合特性

Coupling Characteristics of Photonic Crystal Waveguide Based on Self-imaging of Multi-mode Interference

模拟计算了二维三角形光子晶体波导自成像多模干涉的耦合特性。提出两种不同结构的二维光子晶体分束器,基于自成像多模干涉效应,用有限时域差分法数值计算和分析了这两种分束器的特性。研究发现其中一种分束器的反射率低于10-4,透射率可高达0.9999,而另外一种分束器的反射率为1,透射率为0。分析发现,造成这种现象的物理原因是多模干涉区的自成像效应,这种多模干涉在光子晶体光学集成电路中具有重大的潜在应用价值。

The coupling characteristics of multimode interference effect and self-imaging principle in two-dimensional triangle photonic crystal waveguides are investigated by modeling and computation. Two different two-dimensional photonic crystal splitters are proposed, and their characteristics are calculated and analyzed by using finite-difference time-domain method based on the multimode interference effect and the self-imaging principle. The results show that the reflectivity of one splitter is smaller than 10^-4, but the transmittivity can be larger than 0. 999 9, while for the other one, the reflectivity is 1, but the transmittivity is 0. Through analyses, the self-imaging principle in the multi mode region is thought to he the physical origins of this phenomenon.