Fusion network system for quantum communication and quantum time-frequency transmission and method

Abstract

The invention discloses a fusion network system for quantum communication and quantum time-frequency transmission and method. A quantum relay unit transmits entangled photon pairs and transmits the entangled photon pairs to two quantum terminal units through transmission units respectively; the quantum terminal unit reflects input photons, and the photons are returned to the quantum relay unit through the transmission unit; the quantum relay unit performs HOM interference measurement on the entangled photon pairs, optical path delay is adjusted, the maximum HOM depression value is obtained through multiple times of measurement, and optical path balance is realized. Later, a signal laser transmits laser pulses to the quantum relay unit through the transmission unit, the quantum terminal unit codes the input laser pulses and transmits the laser pulses to the quantum relay unit through a transmission channel, the quantum relay unit obtains a result, an acquired key is published through aclassical channel, clock synchronization is carried out through the classical channel and by using an optical channel monitor, time-frequency information is encrypted through a key distributed by QKD,and thus, the time-frequency information security problem is solved, and fusion between quantum communication and quantum time-frequency transmission is realized.

Description

technical field [0001] The invention relates to the technical fields of quantum information and optical communication, in particular to a fusion network system and method of quantum communication and quantum time-frequency transmission. Background technique [0002] Time frequency is a very important parameter; time frequency standard transmission is also crucial in high-precision timing systems, and it is widely used in many fields such as positioning, navigation, and communication. Time-frequency synchronization technology refers to the process of comparing time-frequency signals generated by clocks in different places by some means, and forming a unified time-frequency reference. Precision navigation is inseparable from accurate timing service, and the basic requirement of timing service is clock synchronization. [0003] With the continuous development of atomic clock technology, the frequency uncertainty of optical frequency atomic clocks reaches 10 -18 . The existin...

AI Technical Summary

Problems solved by technology

First of all, the distance between Alice and Bob is not exactly the same as that of Charlie, and it is necessary to accurately delay the arrival time of photons to be completely aligned.

Secondly, Alice and Bob use different lasers, and the spectrum is not exactly the same

Third, due to the birefringence effect of the fiber, it is difficult to ensure the stable transmission of the photon polarization state

Although phase encoding can be used, phase drift and time jitter limit the improvement of QKD system performance, and the key rate is low

[0006] At the same time, in the existing technology, such as patent 201510008068.9, it tries to solve the stability problem of the measurement equipment independent protocol of phase modulation and polarization encoding, but artificially shortens the communication distance by half

[0007] In the prior art, such as the Gisin group of the University of Geneva in Switzerland who first proposed a plug-and-play solution (document: Muller A, Herzog T, Huttner B, et al. "plug and play" systems for quantum cryptography [J]. Applied physics Letters, 1997 ,70:793-795) adopts the phase encoding method, and the patent 201610700278.9 is further improved, adopting the time phase encoding method, the main purpose is to solve the problem of polarization jitter compensation in the optical fiber, but it does not involve the measurement equipment independent scheme

[0008] The plug-and-play solution can use the same laser to achieve the consistency of photon spectrum and other parameters, but because the distance between the communication parties and the relay is not completely symmetrical, the HOM interference ratio is reduced

At present, in experiments, independent optical pulses of different wavelengths are generally used to achieve synchronization between the two communication parties by using wavelength division multiplexing, which consumes wavelength resources.

However, with the increase of network users, especially in the classical and quantum communication fusion network, each wavelength is a precious resource, the above method is obviously not economical and feasible

[0009] MDI-QKD has high requirements for clock synchronization, but the security of time-frequency transmission cannot be fully guaranteed at present. Combining the advantages of QKD information security and the advantages of high synchronization accuracy of time-frequency transmission, the network that integrates quantum communication and quantum time-frequency transmission is temporarily No related proposals have been seen

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