为了提高硅基光栅耦合封装结构的耦合效率、增大容差范围, 对光栅耦合的结构特性进行了理论分析, 并采用时域有限差分法完成了仿真验证, 在不改变光栅参量的基础上, 对光栅耦合封装结构进行了改进, 仿真建立了一款光栅上方和光纤端面分别增加透镜的优化结构,研究了影响耦合效率的因素。结果表明, 增加透镜后, 耦合效率有所增加, 角度容差和带宽都有一定的优化; 在衬底增加反射镜后, 对波长1550nm的光耦合效率提高至73.809%。该研究结果可为光栅耦合的封装结构设计提供参考依据。

In order to improve the coupling efficiency and increase the tolerance range of grating coupling packaging structure on silicon substrate, the characteristics of grating coupling structure were analyzed theoretically and verified by simulation based on finite-difference time-domain method. After studying the main influence factors of the coupling efficiency, the basic grating coupling structure was improved without changing the parameters of the grating. A grating coupling structure with lenses was proposed. The results show that, after the lenses are added, coupling efficiency, angle tolerance and bandwidth are optimized through simulation. The coupling efficiency is increased to 73.809% with an incident wavelength in 1550nm when adding the reflectors on the substrate. The analysis results provide a reference for the design of the packaging structure of the grating coupling.