Clock synchronization device applicable to quantum communication system

Abstract

The invention discloses a clock synchronization device applicable to a quantum communication system. The device comprises a signal sending end, a signal receiving end and a transmission fiber, wherein the signal sending end is provided with first and second laser pulse generators, first and second delay modules, and a first wavelength division multiplexer, wherein the signal receiving end is provided with a second wavelength division multiplexer, a Bragg grating and a PIN (positive-intrinsic negative) diode; and the transmission fiber is connected to an output end of the first wavelength division multiplexer and an input end of the second wavelength division multiplexer. According to the invention, by adopting the signal time-staggered transmission and wavelength division multiplexing technology, the phase difference between a single photon signal and a synchronous optical signal is controlled by the delay modules, the single photon signal and the synchronous optical signal are coupled to a same fiber for transmission, thereby saving the fiber resource, and ensuring that the synchronous optical signal does not trigger the signal photon signal and result in crosstalk.

Description

technical field [0001] The invention relates to the technical field of quantum communication optical fiber transmission, in particular to a clock synchronization device suitable for quantum communication systems. Background technique [0002] Quantum communication technology is a new type of communication means, especially in the field of confidentiality and security of communication. Quantum communication uses single photon as the information carrier, and realizes the safe and confidential transmission of information between two users through its quantum characteristics. In the specific implementation process of the quantum communication system, the clock synchronization technology is one of the key technologies of the system, which determines the correctness of the key screening and the consistency of the codebooks of both parties during the quantum key distribution. [0003] In the prior art, two optical fibers are usually used in the quantum communication system to resp...

AI Technical Summary

Problems solved by technology

However, this method has a great waste of fiber resources, and due to the different transmission environments of single-photon signals and synchronous optical signals, there is a defect of relative phase jitter in the signal transmission process, which is harmful to systems with high repetition rates. deadly impact

In order to overcome the above defects, engineers and technicians try to use an optical fiber to transmit the synchronous optical signal in which the single photon signal of quantum communication is synchronized with the clock. The crosstalk to the single photon signal makes it impossible to restore the single photon signal and the synchronous optical signal at the receiving end; in the prior art, the single photon signal and the synchronous optical signal are simply coupled by wavelength division multiplexing. However, the accurate separation of the single photon signal and the synchronous optical signal cannot be guaranteed, which will cause a part of the synchronous optical signal to enter the single photon signal, so that the synchronous optical signal will cause a trigger signal to the single photon signal, resulting in a bit error, which affects safety, Accurate Transmission of Confidential Information

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