Patent ID: 7406173
Filing Date: 2008-07-29
Classification: H04B,H04L

Abstract:
1. A quantum communication apparatus, comprising: n numbers of ensembles denoted as A(i),where i=1, 2, 3, . . . , n, n being 2 an optical system for the ensemble A( and an optical filter F an optical system for the ensemble A(n), comprising: an optical system for the ensemble A(j), where j=2, 3, 4, . . . , n−1comprising: an optical shutter S a control circuit configured to selectively open optical shutters corresponding to a particular set of ensembles to be irradiated with pulsed light; beam splitters B pairs of photon detectors D beam splitters B pairs of photon detectors D signal processing circuits connected to the respective pairs of photon detectors and configured to generate signals to close the two optical shutters corresponding to the two ensembles participated in photon detection with either one of a particular pair of photon detectors.