A quantum communication network

摘要

This invention provides a quantum communication system in which multiple transmitters 23 transmit quantum communication signals to a single receiver 21. The transmitters are synchronized with the receiver by means of a common clock which is preferably transmitted from the receiver. A timing mechanism is adopted which ensures that a detector of the receiver receives a signal from only one transmitter at a time, and which allows the receiver to identify the sending transmitter. This appears to be in effect a time division multiple access system (TDMA). The signals from the transmitters are combined in a combining device 24 and the multiplexed signals are sent along a single channel to the detector. The combining device may be an Nx1 passive optical coupler, a fast optical switch, a switchable MEMS mirror or a wavelength division multiplexer (WDM).