基于高速单光子探测的光时域反射测量

Optical time domain reflectometer based on high-speed single-photon detection

针对传统光时域反射仪(OTDR)激光出射功率高、累计时间长、测量分辨率低的问题,提出了将高速InGaAs/InP雪崩光电二极管单光子探测器应用于光时域反射测量的方法.单光子探测器的工作重复频率为1 GHz,可实现"准连续"探测,无需扫频即可快速捕获单光子水平的回返光信号并输出.该方法实现了出射光脉冲宽度为50 ps、峰值功率为10 mW,测量距离为50 km,距离精度小于10 cm,且事件盲区小于1 m的光时域反射测量.

Conventional optical time domain reflectometer （OTDR） not only requires high-power laser output and long cumulative time but also exhibites low resolution. To solve the problem this paper pro- poses an OTDR with a high-speed single-photon detector based on InGaAs/InP avalanche photodiode. The working repetition frequency of this single-photon detector was 1 GHz, achieving ＂ quasi-continu- ous＂ detection, realizing quick capture of return signal at single-photon level without scanning. With the emitting pulsed laser of 50 ps pulse width and 10 mW peak power, this OTDR whose event dead zone is less than 1 m, could obtain the longest measuring distance of 50 km with 10 cm accuracy.