Characterization of a single-photon detector at 1.55 μm operated with an active hold-off technique for quantum key distribution

摘要

To better understand how the active hold-off technique in single-photon detectors (SPDs) based on InGaAs/InP avalanche photodiodes (APDs) enhances the performance of a quantum key distribution (QKD) system based on the BB84 protocol, we have evaluated the dependence of the raw key creation rate (R _(raw)) as well as the quantum bit error rate (QBER) on the number of active hold-off gates. The results of our analysis reveal that at 10 MHz repetition rate of the gate, by holding-off 200 gate pulses immediately following an avalanche event, the afterpulse contribution to the QBER drops down to 2.35% without noticeable decrease in the R_(raw).