Research On High-precision Single-photon Ranging

In the field of laser ranging,pulse-time-of-flight laser ranging based on timecorrelated single-photon counting technology(single-photon ranging)can increase the sensitivity of the ranging system to the single-photon level,which can reduce the laser energy requirements for long-distance ranging,increase the ranging distance,and improve the ranging system's safety performance for human eyes.On the other hand,the development of the national economy and the national defense construction have put forward higher and higher demands for the precision of laser ranging.Among them,the precision of single-photon ranging is mainly affected by two aspects: the time jitter of ranging system and the delay drift of single-photon detector.At present,the precision of single-photon ranging mostly stays at the millimeter level,so it is of great research and application value to carry out higher-precision single-photon ranging.In this work,a single-photon ranging method based on high-precision avalanche photodiode single-photon detector was developed,which realized the single-photon ranging for non-cooperative targets with hundred-micron-level ranging precision.The avalanche photodiode single-photon detector is the most widely used single-photon detector nowadays,which has the advantages of small size,room temperature operation,and high detection efficiency.Through device optimization and detection circuit upgrade,the avalanche photodiode single-photon detector exhibits better time jitter performance.In the system,we used the self-developed silicon-based avalanche photodiode photon detector with a time jitter of 65 ps,combined with an 800 nm band Ti:Sapphire laser with a pulse width of 9 ps,and a high-precision timer with a time jitter of 23 ps to reduce the time jitter of the ranging system.The reference position was brought in the ranging system,which effectively suppressed the system delay drift and enabled the measurement precision of photon flight time to 0.5 ps.The ranging precision of 65 ?m@RMS was realized,while the target was 2 m away.This work is one of the highest levels of pulse time-of-flight ranging,and provides an effective technology for high-precision ranging and imaging of long-range non-cooperative targets.