SENDING END FOR DECOY STATE ENCODING AND POLARIZATION ENCODING, ENCODING METHOD AND QUANTUM KEY DISTRIBUTION SYSTEM

摘要

The present application relates to a sending end for decoy state encoding and polarization encoding, an encoding method and a quantum key distribution system. In the present invention, the sending end may comprise a light source, an encoding module, and a light path fold-back module. The encoding module comprises a phase modulation unit, and is configured to perform first phase modulation on signal light to be encoded by means of the phase modulation unit and perform decoy state encoding on the signal light on the basis of the phase modulation; the light path fold-back module is configured to receive the signal light subjected to the decoy state encoding and fold back same to the encoding module; the encoding module is further configured to perform second phase modulation on the folded-back signal light subjected to the decoy state encoding by means of the phase modulation unit, and perform polarization encoding on the folded-back signal light subjected to the decoy state encoding on the basis of the phase modulation. Therefore, by reusing the encoding module by means of the light path fold-back module, it is possible to configure the encoding module to implement both decoy state encoding and polarization encoding, thereby greatly simplifying the structure of the sending end.