硅基氮化镓波长可调DFB激光器的模拟分析

摘要

基于严格耦合波以及介质平板波导理论，构建了硅基氮化镓分布反馈激光器的二维稳态物理模型。且利用多物理场直接耦合分析软件Comsol Multiphysics求解波动方程，得到了分布反馈激光器在可见光各波段形成单模输出的电场模一维、二维图谱，以及相对应的入射波长与电场模关系曲线。结合硅基光微机电系统技术和微加工技术，本文提出利用悬空的自支撑氮化镓周期可调光子光栅实现分布反馈激光器波长可调。数值模拟表明，在光栅的格子数目、光栅厚度、光栅宽度以及有源层厚度一定的情况下，改变光栅周期可以实现分布反馈激光器输出不同波长激光。理论分析与仿真结果基本一致，证明所建立激光器模型具有一定的合理性，得出的仿真数据为实现分布反馈激光器波长可调提供了有意义的参考。%Based on the rigorous coupled-wave theory and dielectric slab waveguide theory,a two-dimensional steady physical model is constructed for a silicon-based GaN distributed feedback (DFB)laser.The wave equation is solved by multiphysics field coupling analysis software Comsol Multiphysics,one-dimensional and two-dimensional electric field modes of the DFB laser’s single mode output in visible wavelength region is obtained,and the corresponding re-lationship between the incident wavelength and the electric field mode is also obtained.Combined with silicon-based optical MEMS technology and micro-machining technology,a wavelength-tunable GaN DFB laser with self-supported gallium nitride periodic photonic grating is proposed.Numerical simulation shows that different single mode wavelength output from the GaN DFB laser can be realized with a certain number of grating lattice,grating height,grating width and active layer thickness.The theoretical analysis and the simulation results are consistent,which proves that this la-ser model has certain rationality.The simulation data provide a meaningful reference for the realization of the tunable wavelength from the GaN DFB laser.