提出并实现一种基于InGaAs/InP雪崩光电二极管单光子探测器的双重复频率光时域反射仪系统.通过发送两列重复频率有差异的脉冲激光信号对同一光纤的断点进行检测.接收系统采用高速单光子探测器, 保证了回返光探测灵敏度, 同时也提高了数据采样的速度.通过调节两列激光脉冲重复频率, 不仅可以实现系统测量距离量程的改变, 而且能够改变测量精度.

An optical time domain reflectometer with dual repetition rates was proposed based on the single photon detector with InGaAs/InP avalanche photodiode. Two arrays of laser pulses with slight different repetition rates were injected into the fiber to monitor the fiber broken point. A fast single photon detector was adopted for high sensitivity in reflected pulses detection with reduced measurement time. By adjusting the difference of the repetition rates, not only the measuring range of the system can be extended ,but also the measurement accuracy can be changed.