提出了一种基于单光子探测的光纤传输时间峰值扫描测量方法。通过调节门控信号的到达时间以及与光脉冲匹配的开闸宽度,统计单光子探测器的计数率峰值来判断光脉冲的准确到达时刻,避免了单光子探测器在盖格工作模式下输出雪崩脉冲的时间抖动测量误差。在理论分析峰值扫描测量法的基础上,设计了峰值扫描测量实验系统,在长度为125 km光纤信道上测量光脉冲传输时间精度达到35 ps,同时验证了实验系统测量的准确度约为13 ps。
A new method to measure transfer time delay in optic fiber more accurately is proposed to deal with timing jitter of single photon avalanche detector worked in Geiger mode. The arrival time of echo optical signal is determinated by adjusting the arrival time and width of gate signal to make the photon count rate reach the maxim value. The method avoids the intrinsic timing jitter of single photon avalanche detector. After deliberately theory analysis, system experiment is performed in fiber of length approximate 125 km, the experiment shows that measurement precision is about 35 ps and the accuracy is about 13 ps.