Synchronizer and synchronization method for quantum key distribution

Abstract

The invention relates to a synchronizer and a synchronization method for quantum key distribution. The synchronizer is characterized in that the signal output end of a synchronous signal coding module is connected with the signal input end of a synchronous laser transmitting module the signal output end of which is connected with the signal input end of a comparator circuit module through optical fibers; and the signal output ends of an optical detector and the comparator circuit module are respectively connected with the signal input ends of an adjustable time delay circuit which is used to generate door control signals and has adjustable time delay and a synchronous detection and coding module which counts by using one frame counter and codes the synchronous signals. The invention further provides a high-performance quantum key distribution system which uses single optical fiber to transmit signal light and synchronous light in a system with frequency of dozens of megahertz, realizes accurate synchronization of both systems, can realize synchronization again in the case of loss of the synchronization and improves the fault tolerance of the systems.

Description

technical field [0001] The invention relates to a quantum secret communication method, in particular to a quantum key distribution device and a distribution method. Background technique [0002] A key technology of the quantum key distribution system is the synchronization of the information of the sender and the receiver. Only when the information is synchronized and compared can the subsequent key extraction work be carried out. At the same time, it is required to remove the dark count as much as possible to reduce bit errors. Rate. Since the entire system is required to work with high precision, accurate synchronization of information needs to be guaranteed. In order to ensure the accuracy of single photon counting, it is necessary to accurately transmit the synchronization signal from the sending end to the receiving end and keep in sync with the detection signal of the single photon detector. If the synchronization of photons is better, the single photon counting is m...

AI Technical Summary

Problems solved by technology

[0003] At present, many quantum key distribution experiments have been completed at home and abroad. One is to use atomic clocks for synchronization. This synchronization method generally uses second signals for synchronization. For systems with frequencies of several megabytes or even tens of megabytes, second Signal synchronization is a relatively rough solution, and it cannot achieve good synchronization between the two parties, and because atomic clocks are relatively expensive, they are relatively less used

The other is to use simple optical synchronization, which uses one optical fiber as the transmission of synchronous light, and the frequency can also be the same as the frequency of the transmitted signal, but since two optical fibers are used (the other is used as the transmission of signal light), Greatly increased the cost of use

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