Precise multi-channel timing analysis system for multi-stop LIDAR correlation

The development of single photon applications has led to significant research into high-precision timing analysis systems. The requirement of precise time-of-flight measurements, as well as the removal of ambient/dark photon noise has been a driving force in the development of systems which provide a precise timing resolution. The proposed system aims to compute time-of-flight single photon measurements for a Multi-stop Light Detection and Ranging (LIDAR) experiment. This involves precisely computing time-of-flight between an emitted START signal and multiple photon reflections corresponding to STOP signals within a Field Programmable Gate Array (FPGA). The aim of this system is to time-tag photon counts from multiple single photon detectors with a resolution in the tens of picoseconds, where correlation computations are performed in hardware to determine time-of-flight between START and STOP signals. The developed system showed an 8-channel multi-stop timing analysis system and achieved an average resolution of 21.5 ps, with a measurement error of 20 ps Full Width Half Maximum (FWHM). The number of STOPs that can be detected by the system is determined by the deadtime and dynamic range of the TDC. In our design the dynamic range is 2.14 s and the deadtime for each TDC block is 8 ns. From the tests conducted on the time-tag correlator, the capability to record 120 STOPs has been observed.