背景光作用下激光雷达中Si-APD噪声特性研究

发布时间：2019-03-17 09:34

【摘要】：雪崩光电二极管(APD)是一种量子效率高、灵敏度高、频率响应特性好的光电探测器,在激光雷达、微光探测、光纤通信等领域中有着重要应用。大探测视场角脉冲式激光雷达在白天工作时,背景光通常是其APD探测系统的主要噪声来源,因此,有必要探究激光雷达中APD在不同背景光下的噪声特性,以利于APD最佳倍增工作点的设定,提高激光雷达探测信噪比。论文深入调研了国内外关于APD工作原理、噪声成因及理论模型等方面的最新研究成果,以南京理工大学信息与物理工程系研发的激光雷达回波信号接收机为原型,设计了C30950E型Si-APD噪声测量系统。论文使用Tektronix公司生产的TDS5054B型数字示波器对APD噪声信号进行采样,并根据数字信号处理和数理统计理论,使用Matlab和Origin软件对噪声数据进行分析,深入研究了不同背景光条件下激光雷达系统中Si-APD的噪声特性。根据对噪声数据的统计分析,论文给出了在恒定温度环境下,APD噪声电压有效值与入射背景光功率、APD偏置电压之间的关系,探讨了饱和现象对APD工作性能的影响；指出APD工作在线性模式时,在本文选定的背景光入射条件下,APD探测系统的噪声幅度概率分布均为高斯分布；通过对APD噪声功率谱的分析,明确了噪声功率谱特征及APD探测系统带宽。本次论文研究为激光雷达光学接收系统的设计提供了依据,有利于激光雷达最佳工作状态的确定和信噪比的改善,在激光雷达领域有重要应用。
[Abstract]:Avalanche photodiode (APD) is a kind of photodetector with high quantum efficiency, high sensitivity and good frequency response. It has important applications in the fields of laser radar, low light level detection, optical fiber communication and so on. Background light is usually the main source of noise in the APD detection system of large field of view pulse lidar during daytime work. Therefore, it is necessary to explore the noise characteristics of APD in Lidar under different background light, so it is necessary to explore the noise characteristics of APD in Lidar under different background light. In order to improve the signal-to-noise ratio (SNR) of Lidar detection, the optimal operating point of APD is set. In this paper, the latest research results about the working principle, the cause of noise and the theoretical model of APD at home and abroad are deeply investigated. The prototype is the Lidar echo signal receiver developed by Nanjing University of Science and Technology's Information and physical Engineering Department. A C30950E Si-APD noise measurement system is designed. In this paper, TDS5054B digital oscilloscope produced by Tektronix company is used to sample the APD noise signal. According to the theory of digital signal processing and mathematical statistics, the noise data are analyzed by Matlab and Origin software. In this paper, the noise characteristics of Si-APD in Lidar system under different background light conditions are studied in depth. According to the statistical analysis of the noise data, the relationship between the effective value of the APD noise voltage and the incident background light power and the APD bias voltage under the constant temperature is given, and the influence of saturation on the performance of the APD is discussed. It is pointed out that when APD works in linear mode, the probability distribution of noise amplitude of APD detection system is Gao Si distribution under the background light incidence condition selected in this paper. Through the analysis of APD noise power spectrum, the characteristics of noise power spectrum and the bandwidth of APD detection system are defined. This paper provides a basis for the design of Lidar optical receiving system, which is conducive to the determination of the optimal working state and the improvement of signal-to-noise ratio of lidar. It has important applications in the field of lidar.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN958.98

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