用于APD激光探测的电荷灵敏前置放大器设计

雪崩光电二极管（APD）作为探测元件实现光电转换广泛应用于激光脉冲探测技术中。前置放大器是影响APD激光脉冲探测系统好坏的关键因素，前置放大器的信噪比决定了整个探测系统的信噪比优劣。提出了电荷灵敏前置放大器应用于APD激光脉冲探测系统以提高探测距离和探测精度的方法。讨论了激光脉冲探测技术和APD特性，在此基础上设计了以结型场效应管和集成运放为主要器件的低噪声电荷灵敏前置放大器电路并对设计电路进行了实验分析。实验结果表明：将电荷灵敏前置放大器应用于APD激光脉冲探测系统可以有效提高系统的信噪比，改善激光探测性能。

Charge sensitive preamplifier design for APD detection system of laser pulse

As a new photoelectrical detector,avalanche photodiode (APD) has been widely used in the detection system.Preamplifier is one of the key factors which affect APD detection system of laser pulse.The signal-to-noise ratio (SNR) of preamplifier determines the SNR of whole detection system.A method that charge sensitive preamplifier used in APD detection system of laser pulse was presented to enhance the range and precision of the detection system.The APD detection technology of laser pulse and the characteristics of APD were discussed,and a low noise charge sensitive preamplifier circuit which designed by JFET and integrated-circuit operational amplifier was described.This circuit has advantages of low noise,small size and simply structure,etc.The circuit was analyzed in experiment.The experimental results prove that the charge sensitive preamplifier used in APD detection system of laser pulse can effectively improve the signal-to-noise ratio and the performance of detection system.