Patent ID: 7492900
Filing Date: 2009-02-17
Classification: H04B,H04L

Abstract:
1. A quantum communication system comprising: an emitter configured to emit a plurality of photon pulses in groups of photon pulses, each group of photon pulses emitted over a group time period, wherein the average number of photons per pulse is less than 1; a detector comprising gating means configured to switch the detector between an on state and an off state; wherein the separation between pulses in said group of pulses is less than the time when a detector may register an after pulse signal or a false positive reading, the detector is in an on state for at least the duration of two photon pulses during said group time period, and the system is configured to ignore a second or subsequent pulse received by the detector in a group time period after a first pulse has been detected for the group of pulses.