High-speed laser ranging using linear/Geiger dual-mode detector in the near-infrared with InGaAs/InP SPAD

Focusing on the characteristics of large variation ranges in target signals and background noise in near-infrared Light Detection and Ranging (LiDAR) applications, this paper proposes a method of Linear/Geiger dual-mode detection based on InGaAs Avalanche Photodiodes (APDs) to meet the requirements of higher dynamic range response. Two structures combining an active quenching circuit and a transimpedance amplifier circuit were designed, and the dual-mode detection performance of the two designs was compared. Furthermore, the detector can achieve linear/Geiger dual-mode switching through rapid bias control based on Field-Programmable Gate Array (FPGA) and high-speed operational amplifiers. The results show that the developed detector can achieve Linear/Geiger dual-mode detection, enhancing the dynamic range of photon detection. The dual-mode detector also integrates functions such as gating, parameter control, and time-correlated single-photon counting (TCSPC). For practice, we conducted laser ranging experiments using this dual-mode near-infrared photon detector, achieving high signal-to-noise ratio ranging results from short distances to as far as 52 km through the switching of dual modes. This highly integrated dual-mode detector in the communication band is particularly suitable for applications with large dynamic ranges in echo photon numbers and more stringent requirements on performance and operating environment.