Quantum communication system
AssigneeKabushiki Kaisha Toshiba
InventorsAndrew James Shields, Zhiliang Yuan
Life of this patent
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Abstract
A quantum communication system including an emitter and a receiver, the emitter including an encoder and at least one photon source and being configured to pass a signal pulse and a reference pulse, which are separated in time, through the encoder and output the signal pulse and the reference pulse. The reference pulse has a higher probability of containing more than one photon than the signal pulse. The receiver includes a decoder and at least one detector for measuring the signal pulse and the reference pulse.
Claims15
A quantum communication system comprising an emitter and a receiver, said emitter comprising an encoder and at least one photon source, said emitter configured to pass a signal pulse and a reference pulse, which are separated in time, the signal and reference pulses being separated in time prior to entry into said encoder, said receiver comprising a decoder and at least one detector for measuring said signal pulse and said reference pulse, wherein the signal pulse is encoded as said signal pulse passes through the encoder and the reference pulse when passing through the encoder is encoded with information which is uncorrelated with that of the encoding of the signal pulse, wherein a reference detector is configured to detect variations in the phase of said reference pulse;
- and wherein said receiver further comprises an integrator for integrating a count value of said reference detector.
A method of communicating photon pulses from an emitter to a receiver, comprising:
- generating a signal pulse and a reference pulse separated in time in an emitter;
- passing both the signal pulse and the reference pulse through the same encoder in said emitter and sending said pulses to a receiver, said signal pulse and reference pulse being temporally separated as they enter said encoder, wherein the signal pulse is encoded as the signal pulse passes through the encoder and the reference pulse when passing through the encoder is encoded with information which is uncorrelated with that of the encoding of the signal pulse;
- and
- measuring both the signal pulse and the reference pulse in said receiver, including detecting variations in the phase of said reference pulse, and integrating a count rate of said reference pulse.
A method of outputting photons from an emitter, the method comprising:
- generating a signal pulse and a reference pulse separated in time in an emitter;
- passing both the signal pulse and the reference pulse through the same encoder in said emitter and outputting said pulses, wherein the signal pulse is encoded as the signal pulse passes through the encoder and the reference pulse when passing through the encoder is encoded with information which is uncorrelated with that of the encoding of the signal pulse;
- detecting variations in the phase of said reference pulse;
- and
- integrating a count rate of said reference pulse.
Dependencies are inferred from the claim text.