High speed single-photon detector at 1550 nm wavelength

A single photon detector operating in the Geiger mode was cooled to a moderate temperature by using Peltier cooling and heat pipe technology, and a gate pulse signal was coupled to the avalanche diode by a capacity. A moderate delay and edge trigger flip flop were used to avoid the positive and negative transient pulses from influencing the detection of true photon avalanche, a dead time modulation feedback control circuit was used to decrease the after-pulsing, and the working frequency of the detector was improved by ECL (Emitter Couple Logic) and TTL (Transistor-Transistor Logic) technologies which was greatly larger than 10 MHz. In addition, the signal dynamic range was improved through amplifying avalanche signal and the detector performance was further optimized. On the condition that the temperature is -62°C, the minimum gate pulse width is 8 ns, and the clock frequency is 10 MHz, it is found that at the optimum operation point the quantum efficiency is about 12.8%, the dark count rate is 3.76×10-6 ns-1 and the noise-equivalent power is 8.68×10-19 W/Hz1/2 from the performance test and analysis.