Gaussian pulse gated InGaAs/InP avalanche photodiode for single photon detection

The capacitive response noise has been problematic for high-speed single photon detection based on gated InGaAs/InP avalanche photodiodes. Traditionally, the noise must be suppressed by complex electronic circuit if low afterpulse probability is desired. In this Letter, we propose a compact and flexible method for noise cancellation, which gates the photodiode with a Gaussian pulse. Because of the differential effect of junction capacitor, the shape of the capacitive response output in our method is the first-order derivative of the Gaussian function that can be matched by the rising edge of a delayed and attenuated version of the gating pulse itself. With matching signal, the avalanche pulse is raised onto a flat platform that can be easily discriminated from the background. For 1550 nm optical signal, the detection efficiency could reach 10.2% with 9.7×10(-6) per gate dark count probability and 3.4% afterpulse probability at 80 MHz gating frequency. Experimental results have shown that the proposed method can decrease the afterpulse probability sharply while maintaining the detection efficiency and dark count performance.