Performance of Commercially Available InGaAs/InP SPAD with Custom Electronics

Abstract

InGaAs/InP devices suitable as Single-Photon Avalanche Diodes (SPADs) for photon counting and photon timing applications in the near-infrared provide good detection efficiency and low time jitter, together with fairly low dark-count rate at moderately low temperatures. However, their performance is still severely limited by the afterpulsing effect, caused by carriers trapped into deep levels during the avalanche current flow and later released. We present preliminary experimental characterization of recently-developed InGaAs/InP detectors that can promisingly be operated slightly cooled. We investigate the primary dark-count rate, taking into account both thermal generation in the InGaAs absorption layer and trap-assisted tunnelling in the InP multiplication layer. The fundamental role played by the front-end circuits in minimizing the effects of afterpulsing is assessed and demonstrated.