为了利用悬空的周期可调光栅控制激光器的波长输出, 采用了微机电系统技术中微驱动器与分布反馈激光器光栅相结合的结构, 根据严格耦合波理论和介质平板波导理论, 针对光通信的C波段, 利用有限元软件COMSOL, 建立了基于氮化镓的波长可调分布反馈激光器2维稳态模型。分析了1550nm处2维电场模式图以及激射波长线宽图, 得到了激射波长与光栅周期的对应关系。结果表明, 在光栅厚度、高度以及增益层厚度等结构参量一定的情况下, 激射波长与光栅周期呈现与理论分析基本一致的似线性关系。该研究为该器件设计以及制备的后期工作开展提供了理论指导意义。

In order to control laser wavelengths output of laser by suspending period-adjustable gratings, a structure combining microdriver of micro-electro-mechanical system(MEMS) technology with grating of distributed feedback (DFB) laser was proposed. According to rigorous coupled-wave theory (RCWA) and medium slab waveguide theory, using infinite element software COMSOL, a two-dimensional steady physical model of wavelength-adjustable DFB laser based on GaN was constructed for C-band in optical communication. 2-D electric field mode picture and lasing wavelength linewidth picture at 1550nm were analyzed and the corresponding relationship between grating period and lasing wavelength was gotten. The results show that, with certain structural parameters such as grating lattice thickness, height and gain layer thickness, lasing wavelength and grating period present similar linear relationships being consistent with theoretical analysis. The study will give good theoretical guidance for carrying out the design and preparation of the device.