US Patent 7822342 Secure quantum optical communications system and method

An optical communication system is provided. In one embodiment, a source creates a multiplicity of photon pairs, with each photon pair comprising a first photon and a second photon. The first photon is sent to a transmitter, and either remains in the transmitter or is transmitted by the transmitter to a receiver. The second photon is sent to the receiver. Data is decoded by determining a polarization direction and a time of detection of any photon pairs detected at the receiver.