传统的单光子探测器仅能区分“有”或“无”两种光子态，然而量子计算、量子通信、光场量子特性测控等应用要求其能够区分具体光子数目，即实现光子数可分辨探测。InGaAs/InP雪崩光电二极管（APD），探测性能良好，易于集成且功耗低，是近红外通信波段光子检测的最佳选择之一。通常，InGaAs/InP APD工作在门控盖革模式，极易发生增益饱和，无法进行光子数可分辨探测。同时，因APD容性效应产生的尖峰噪声信号会将有效的光生雪崩信号湮没，随着工作速率的提高，雪崩时间缩短，进一步增大雪崩信号的提取难度。此外，时间抖动特性也是影响高速光子数可分辨探测的重要因素。本项目旨在实现基于InGaAs/InP APD的高速光子数可分辨探测，发展频谱分析及滤波平衡相结合等方案，增加尖峰噪声抑制比的同时减小时间抖动，实现GHz光子数可分辨探测，并拓展其在高速随机数产生、激光测距及成像等领域的应用。

The traditional single-photon detector can only distinguish between “yes” or “no” two photon states. With the development of quantum information, the capability of photon-number resolution is increasingly crucial to many applications, such as quantum computation, quantum communication, measurement and control of optical field quantum properties, and so on. With the characteristic of good detecting performance, easy integration and low power consumption, InGaAs/InP avalanche photodiode (APD) is one of the best choices for single-photon detection in the near infrared communication band. In general, InGaAs/InP APD works in the gated Geiger mode, leading it easily to reach gain saturation, and cannot achieve photon-number-resolving detection. Meanwhile, the effective avalanche signals are buried in the spike noise generated by the APD capacitive effect. With the increase of the working speed, the avalanche time is shortened, and the difficulty of extracting the avalanche signal is further increased. In addition, the timing jitter is also an important factor which affects high-speed photon-number-resolving detection. The purpose of this project is to realize InGaAs/InP APD based high-speed photon-number-resolving detection, develop the scheme of combining the frequency spectrum analysis and filtering balance, increase spike noise suppression ratio with reducing the timing jitter to achieve GHz photon number resolving detection, and expand its applications in high-speed random number generation, laser ranging and imaging and other fields.