Photodetector For Laser Ranging And Speed Ranging

At present, there are mainly three avalanche suppression modes for InGaAs APDs: passive suppression, active suppression and gated detection. Passive suppression increases the dead time of avalanche photodiodes and seriously reduces the maximum count rate of the detector, while active suppression is too complicated because the suppression circuit is too complicated and the signal cascade is prone to emission. The gated detection mode is currently used in single-photon detection. The most widely used.

Single-photon detection technology can effectively improve the accuracy and detection efficiency of the system. In the space laser communication system, the intensity of the incident light field is very weak, almost reaching the photon level. The signal detected by the general photodetector will be disturbed or even submerged by the noise at this time, while the single-photon detection technology is used to Measure this extremely weak light signal. The single-photon detection technology based on gated InGaAs avalanche photodiodes has the characteristics of low after-pulse probability, small time jitter and high count rate.

Laser ranging has played an important role in many fields such as industrial control, military remote sensing and space optical communication due to its precise and fast characteristics, and with the continuous progress of optoelectronic technology. Among them, in addition to the traditional pulse ranging technology, some new ranging solutions are constantly proposed, such as the single-photon detection technology based on the photon counting system, which improves the detection efficiency of a single photon signal and suppresses noise to improve the system. ranging accuracy. In single-photon ranging, the time jitter of the single-photon detector and the laser pulse width determine the accuracy of the ranging system. In recent years, high-power picosecond lasers have developed rapidly, so the time jitter of single-photon detectors has become a major problem affecting the resolution accuracy of single-photon ranging systems.