Research On Dark Count Characteristics Of InGaAs(P)/InP Near-Infrared Single Photon Detector

The near-infrared single photon detector based on InGaAs(P)/InP single photon avalanche diodes(SPADs)has low power consumption,without ultra-cryogenic refrigeration,high reliability,easy to use,integration,high near infrared photon detection efficiency.Many application need SPAD,such as quantum key distribution(QKD)in the field of optical communication,laser ranging and other frontier fields,but the dark count rate of SPAD remains to be improved.Near-infrared single photon detectors(SPDs)based on InGaAs(P)/InP SPAD mainly include InGaAs(P)/InP SPAD and its driving circuits,both of the circuits and SPAD have an effect on the performance of SPD.In this paper,we studied the dark count of near-infrared SPD based on InGaAs(P)/InP SPAD and dark counts' influencing factors,the dark current of SPAD in the Geiger mode and its impacts.The relationship between the dark count and dark current being explored provides guidance for the performance optimization of SPAD and SPD.Temperature measurement platform for SPAD was used to study the dark current in the Geiger mode.The light response curve and the edge breakdown of SPAD were studied by using laser beam induced current mapping system.The fast active-quenching circuit for free-running SPAD has been completed in order to test the dark count of different SPADs.The correlation between dark current of SPAD and dark count of the corresponding SPD was explored.It is found that the dark current slope at the avalanche breakdown voltages is related to the dark count.The slope of dark count curve is small,corresponding dark count also is few.There are jitter in the dark current in the Geiger mode and dark count,which are negatively correlated with the temperature and are independent on the excess bias voltage.At present,the study of the dark count mainly focus on the impact mechanism,and the reports of the above results were not found.