Thermal radiation effect in near infrared single photon detector

Aminiaturized near infrared single photon detector is demonstrated by integrating a thermoelectric cooler (TEC), a thermistor, and a planar type InGaAs/InP separate absorption, charge and multiplication structure single photon avalanche diode into a butterfly case. The performance of the device at different temperatures is tested. It can achieve 20.3% single photon detection efficiency and 1.38 kHz dark count rate when the chip is cooled to 223 K. The test results show that even when the chip temperature is kept constant, the dark count rate of the device still increases with the increase of ambient temperature, which is consistent with the carrier generation mechanism of semiconductor materials. The mechanism is researched and it is found that thermal radiation of the high temperature case is the main source of dark count. The deep research on the mechanism is beneficial to developing higher performance devices in the future.