为了研究调Q二极管泵浦固体激光器(DPL)激光脉冲输出的稳定性，利用电路网孔法对传统硅光电二极管探测电路进行了分析，发现传统的探测电路无法检测到激光脉冲中多纵模所引起的高频噪声信号(在腔长小于10cm的短谐振腔中其频率通常为1～2GHz)。根据分析结果，改良了硅光电二极管探测电路，利用高速采样示波器采集到了调Q DPL激光脉冲中(1～2)GHz的高频噪声信号。

In order to investigate the output stability of Q-switched diode-pumped laser (DPL)pulse,the tradition detection circuit of the silicon photodiode was analyzed with the circuit mesh method. It is found that the traditional detection circuit is unable to detect the high frequency noise signal generated by the multi-longitudinal modes in the laser pulse. According to the analysis result,the silicon photodiode detection circuit was improved,and (1～2) GHz high frequency noise signal of a Q-switched laser was collected by the high speed sampling oscilloscope.