High-speed And Low-noise Single-photon Detection Based On Capacity Balancing

Near infrared single-photon detectors (SPDs) are widely used in many fields, such as quantum secure communication, fiber optical sensing, and ultrasensitive spectroscopy. The InGaAs/InP single-photon avalanche photodiodes (SPADs) based on capacity balancing technique can easily tune the gating frequencies without changing any state of the SPAD and have been widely used. But there is a problem that the gating frequencies of the SPADs are under100MHz. The gating frequencies are not suitable for quantum secure communication now. How to increase the gating frequencies has become the target of this thesis.In this thesis, we propose the capacitance-balancing technique to solve the problem, easily tuning the gating frequencies without changing any state of the SPAD. We have optimized capacitance-balancing technique, refrigeration system and some other modules to continuously tune the gating frequencies of the SPAD from1MHz to200MHz. At200MHz, we obtained a detection efficiency of10%with an afterpulse probability of3.3%and a low dark count rate (1.9×10-6/pulse). These make the device suitable for quantum secure communication, which requires that the bit error rate is less than5%.