An on-chip decoder and decoding method for polarized bb84 protocol

Abstract

The invention discloses an on-chip decoder and a decoding method for polarizing a BB84 protocol. The on-chip decoder comprises an input waveguide (100) and a polarization beam splitting rotator (200), a first light beam splitter (301) and a second light beam splitter (302) provided behind the polarization beam splitting rotator (200); 2 * 2 interference couplers (500), wherein a light path between the first interference coupler (501) is and the first light beam splitter (301), a light path between the second interference coupler (502) and the second light beam splitter (302), a light path between the first interference coupler (501) and the third interference coupler (503), and a light path between the second interference coupler (502) and the fourth interference coupler (504) are respectively provided with a phase bias modulator; and an output waveguide (600) which is used for outputting the decoded signal light. The decoder and the decoding method can realize passive demodulation of polarization BB84 protocols under different preparation bases, and for polarization imbalance in an optical fiber channel, the decoder can realize accurate compensation through on-chip regulation and control.

Description

technical field [0001] The invention relates to the technical field of quantum communication and integrated optics, in particular to an on-chip decoder and a decoding method for the polarization BB84 protocol. Background technique [0002] Quantum cryptography is the product of the combination of quantum mechanics and cryptography, which solves the problem of key distribution in classical cryptosystems. It uses the basic principles of quantum mechanics - the uncertainty principle and the non-cloning theorem of single quantum states, to ensure that the data in the public channel does not have to worry about being eavesdropped during the key distribution process. The currently recognized quantum key distribution devices are mainly based on traditional discrete optical prisms or fiber optic devices, which are bulky, difficult to integrate, and costly, which is not conducive to large-scale commercialization. With the development of silicon-based photonics, the functions of disc...

AI Technical Summary

Problems solved by technology

[0004] Based on the above technical problems, the present invention provides an on-chip decoder and decoding method for the polarized BB84 protocol, which is used to solve the problem of the large size and high cost of discrete components in the traditional solution and the inability to make polarized BB84 under different preparation bases in the prior art. Protocol demodulation, inability to achieve on-chip polarization compensation, etc.

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