隐埋“月牙”形InGaAsP/InP激光器动态特性研究

本文用计算机模拟方法分析了隐埋“月牙”形InGaAsP/InP激光器的动态特性,得到阈值电流,单模截止条件与有源区厚度(中心)d₀、沟宽W、条宽s、腔长L和材料的电阻率R_x等结构参数间的关系。在模拟分析的基础上,提供了阈值电流与结构参数间的近似表示式,从中能简捷地估算激光器的物理特性。文内还提出了注入载流子浓度高斯分布模型,应用这模型,可准确地计算电流扩展和增益分布,且导出了最大增益g_max,阈值电流密度J_th,模增益G_th,最佳有源区(中心)厚度d_0,min,最佳阈值电流密度J_th,min等一系列解析式。基于上述分析,该激光器最佳设计参数为d₀=0.15—0.2μm,W=2—4μm,s=10—15μm,L=200μm。 关键词：

AN INVESTIGATION OF DYNAMIC CHARACTERISTIC FOR THE BURIED CRESCENT InGaAsP/InP LASER

In this paper, the dynamic characteristic of the buried crescent InGaAsP/Inp laser is analysed by the computer simulation method. The dependences of the threshold current and the single model cut-off condition on the structure parameters such as the active layer thickness (centre) d₀, the channel width W, the cavity length L, the stripe width s, and the material resistance R_x are obtained.Based on the simulation analysis, the approximate expression between the structure parameters and the threshold current is provided. From this, the laser physical characteristic can be estimated simply and directly, and the model of injection carrier Gaussian profile is also propounded. Using this model, the current spreading and the gain profile were correctly calculated, and a series of analytical expressions about the maximum gain g_max, the threshold current density J_th, the mode gain G_th, the optimal active layer thickness d_0,min and the optimal threshold current density J_th,min ate derived. According to the analysis mentioned above, the optimal design parameters for this type of laser are obtained as follows:d₀= 0.15-0.2 μm, W = 2-4 μm, L = 200 μm and s= 10-15μm.