随着各种通信业务的不断发展, 光通信网络的容量仍在快速增长，对高速、高灵敏度雪崩光电探测器（APD）的需求不断上升，但目前APD性能远滞后于日益增长的要求，亟待研究提高。近年研究发现，APD过剩噪声不仅依赖于倍增层材料性质（如空穴、电子离化率系数），还依赖于倍增层厚度，采用超薄倍增层可提高器件增益带宽积并减小噪声。本项目拟从更本质的材料特性（如带隙、载流子有效质量、声子散射几率、碰撞电离能等）和结构参数出发，采用蒙特卡洛和有限元的数值法将结构和材料参数统一起来，以更接近物理本质的参数和概念来描述高速低噪声APD的性能（如增益、带宽、过剩噪声和探测灵敏度等），以寻找器件优化规律；同时研究器件噪声的测试方法，精确获得过剩噪声，以正确评估器件性能。通过以上研究，拟构建采用高性能材料和高速器件结构的创新性APD器件，得到超高增益带宽积分离吸收电荷倍增收集型APD测试结果,大幅提升目前研究水平。

With the continuous development of various communication services, the capacity of optical communication network is still growing rapidly. The demand for high-speed and high-sensitivity avalanche photodetector (APD) is increasing, but the progress of APD performance is lagging behind in the growing Requirements. Much more effort is needed to improve the APD properties. In recent years, it has been found that APD uses ultra-thin multiplication layer to improve the device gain bandwidth product while reducing the noise. The excess noise depends not only on the properties of the multiplier layer material (such as hole and electron ionization coefficient), but also on the thickness. The use of ultra-thin multiplication structure is a feasible way to improve the performance level of existing APD devices. The project aims to use the Monte Carlo and finite element numerical methods and the more essential material properties (such as band structure, carrier effective masses, phonon scattering probability, ionization energy, etc.) to describe the high-speed low-noise APDs’ performance (such as gain, bandwidth, excess noise, and detection sensitivity, etc.) , and find the optimization rules of the device. At the same time, we will study the device noise test method, hope to obtain accurate excess noise to describe the device performance properly. Through the above research, we will complete the innovative photomultiplier devices using high-performance materials and high-speed device structure, get ultra-high gain bandwidth product separation-charge-absorption-multiplication-collection APD, and greatly enhance the current research to a higher level.