Continuous variable quantum key distribution system based on Faraday-Michelson interference

Abstract

The invention discloses a continuous variable quantum key distribution system based on Faraday-Michelson interference. A transmitting end is used for generating a pulse light source which is in accordance with the parameters such as repetition frequency, pulse width and so on, and modulating regular components X and P of a signal light; a communication channel is a light propagation channel, and used for transmitting the signal light modulated by the transmitting end and an unmodulated local oscillation light to a receiving end; a receiving end demodulation module realizes measurement and component selection: X or P; and a receiving end zero-difference detection module is used for performing detection processing, and acquiring modulation information data of a signal. The continuous variable quantum key distribution system based on the Faraday-Michelson interference provided by the invention introduces two unequal-arm Faraday-Michelson interference rings, and with the help of a Faraday polarization rotating mirror, the polarization scrambling in a pulse round trip process can be self-compensated, which is beneficial to improving the stability of the system and not easily interfered by polarization; and besides, long distance stable quantum key distribution can be realized in combination with an existing detection technology and a post-processing algorithm.

Description

technical field [0001] The invention relates to a quantum key distribution scheme, in particular to a Faraday-Michelson interference continuous variable quantum key distribution system. Background technique [0002] Since the idea of ​​using continuous variable quantum key distribution (CVQKD) to realize quantum communication was proposed in 1999, CVQKD has attracted the attention of many scholars. Compared with the well-researched discrete variable quantum key distribution DVQKD. CVQKD gets rid of the constraints of single-photon source and low detection efficiency in the 1550nm band. It adopts strong light communication with the same intensity as classical light, and uses mature homodyne detectors in traditional communication for measurement, enabling higher key generation rate and Integration with traditional optical networks has become possible. [0003] In 2002, the CVQKD protocol based on Gaussian modulation was proposed. Subsequently, the unconditional security of t...

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Problems solved by technology

[0005] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and provide a continuous variable quantum key distribution system based on Faraday-Michelson interference. The system of the present invention can overcome the key distribution caused by polarization drift in the continuous variable quantum key distribution scheme System instability problem

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