Afterpulsing characteristics of InGaAs/InP single photon avalanche diodes

InGaAs/InP single photon avalanche diodes (SPADs) are more and more available in many research fields. They are affected by afterpulsing which leads to a poor single photon detection probability. We present an InGaAs/InP avalanche photodiode with an active quenching circuit on an application specific integrated circuit (ASIC). It can quench the avalanche rapidly and then reduce the afterpulse rate. Also this quenching circuit can operate in both free-running and gated modes. Furthermore, a new technique is introduced to characterize the influence of the higher order of afterpulses, which uses a program running on a field programmable gate array (FPGA) integrated circuit.