One-dimensional modulation continuous variable quantum key distribution system based on heterodyne detection, and implementation method thereof

Abstract

The invention discloses a one-dimensional modulation continuous variable quantum key distribution system based on heterodyne detection, and an implementation method thereof. Pulse laser is divided bya first beam splitter into signal light and local oscillator light at a sending end, an electro-optic phase modulator modulates the signal light, and the modulated signal light is attenuated to a quantum level by an adjustable light attenuator; the signal light at the quantum level is merged with the local oscillator light by a polarization coupler and is transmitted to a receiving end by a quantum channel; signal detection is performed on the receiving end by the heterodyne detection technology, the output information of a first differential amplifier and a second differential amplifier are sent to a data collection card and a computer system for collection and analysis processing, and a group of safe quantum keys is obtained on the sending end and the receiving end separately. Accordingto the one-dimensional modulation continuous variable quantum key distribution system, the modulation process in the continuous variable quantum key distribution system can be achieved just by one electro-optic phase modulator, thereby effectively simplifying the system structure, reducing the volume of the device, reducing the data processing volume and reducing the manufacturing cost.

Description

technical field [0001] The invention belongs to the technical field of optical fiber quantum communication, and relates to a one-dimensional modulation continuous variable quantum key distribution system based on heterodyne detection and an implementation method thereof. Background technique [0002] Quantum key distribution enables legitimate communication parties to safely share keys in an untrusted quantum channel, and its security features are based on the uncertainty principle of quantum mechanics and the quantum non-cloning theorem. At present, quantum key distribution is divided into two directions: discrete variable and continuous variable according to the difference of information carrier. Compared with the discrete variable quantum key distribution protocol, the quantum state of the continuous variable quantum key distribution is easier to prepare, can be integrated into the existing optical fiber system, and can use high-efficiency and low-cost homodyne detection ...

AI Technical Summary

Problems solved by technology

The one-dimensional scheme simplifies the modulation method of the signal light while ensuring the safety of the system. The one-dimensional Gaussian modulation of the signal light can be realized through a phase modulator. However, most of the principle experiments use homodyne detection devices and require additional phase modulators, therefore, a more simplified 1D modulated continuous variable quantum key distribution system is urgently needed

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