说明：  针对高增益的光通信用APD的边缘击穿，利用MATLAB得到APD的内部电场分布。运用该模型研究倍增层的厚度对边缘提前击穿特性的抑制程度。
(The breakdown for the edge of the high-gain optical communication APD, using MATLAB APD internal electric field distribution. The use of the thickness of the multiplication layer of the model study in advance on the edge of the breakdown characteristics of the degree of inhibition)