为了讨论三腔镜近似或耦合腔近似两种等效腔模型对计算光纤光栅外腔半导体激光器等效反射率等参量的近似程度, 挑选出最优的理论模型, 采用数值计算的方法进行模拟仿真, 得到了两种模型在采用切趾光纤Bragg光栅和非切趾光纤Bragg光栅情况下的阈值增益等特性曲线。结果表明, 在采用切趾光纤Bragg光栅, 特别是切趾深度较大的情况下, 采用三腔镜近似模型更加符合实际情况。此研究结果对分析和设计单纵模光纤光栅外腔半导体激光器具有一定的参考价值。

In order to discuss approximation degree of calculating equivalent reflectivity and other parameters of the fiber Bragg grating external cavity laser diode by using two equivalent cavity models of the three cavity mirrors approximation or the coupled cavity approximation and choose the best one, the threshold gain characteristic curves of two approximation models by using apodized fiber Bragg grating and normal fiber Bragg grating were gotten after numerical caculation and simulation. Numerical analysis results show that three cavity mirrors approximate model is more in line with the actual situation when using the apodized fiber Bragg grating. This conclusion has the reference in analysing and designing single longitudinal mode fiber grating external cavity semiconductor laser.