Effect of cell size on ambient light rejection in SiPM-based Time-of-Flight range sensors

Silicon PhotonMultipliers (SiPM) have recently been proposed for Time-of-Flight ranging applications thanks to their high gain and excellent performances in terms of timing resolution. This work reports on the preliminary evaluation of a SiPM-based receiver for a Time-of-Flight (ToF) range meter at different ambient light intensities. A low-power 10-MHz picosecond pulsed laser was used as a light source and a Time-Correlated Single Photon Counting (TCSPC) module was employed to measure the time delay distribution between the emitted and reflected laser signal. Three different SiPMs with the same active area of 1×1 mm² but different cell-size (40×40 pm², 20×20 pm² and 15×15 pm²) have been considered for the receiver. The system dynamic range, distance measurement precision and accuracy have been analysed at different ambient light intensities. Devices with smaller cell size exhibit greater ambient light rejection, with a better single-shot precision, a time walk lower than 25ps and a factor 3 improvement in the maximum tolerated ambient light intensity.