Weak correlation single photon source producing method used in gigahertz quantum secret communication system

Abstract

The invention relates to quantum secret communication type, in particular to a weak correlation single photon source producing method used in a gigahertz quantum secret communication system. The method mainly comprises the following four basic steps: automatic gain control, mainly converting clock input signals into sine signals of constant power; narrow pulse generation, mainly producing output of the sine signals into narrow pulse with an order of magnitude of smaller than 200 ps; narrow pulse amplification, mainly amplifying the narrow pulse; and laser diode driving biasing, mainly providing biasing current and modulated current for a laser diode. The method has the advantage that the weak correlation single photon source producing method can realize weak correlation single photon source with the characteristics of high repeat frequency, high extinction ratio and high stability.

Description

technical field [0001] The invention relates to quantum security communication, in particular to a method for generating a weakly coherent single photon source with high repetition frequency, high extinction ratio and high stability for a gigahertz quantum security communication system. Background technique [0002] Quantum secure communication technology originated at the end of the last century. Since Bennett and Brassard jointly proposed the "BB84 Protocol" in 1984, the research and invention around this technology have made great progress. From the initial panic about the security of traditional cryptography, to today's practical quantum secure communication system has been out of the laboratory for pilots. Quantum secure communication technology will enter our life in the near future. [0003] The single photon source is the core module of the quantum secure communication system. The sending end loads the key on the single photon pulse sequence, transmits it through th...

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Problems solved by technology

[0006] The object of the present invention is to provide a method for generating a weakly coherent single photon source for a gigahertz quantum security communication system according to the above-mentioned deficiencies in the prior art. Difficulties in optical pulse width jitter and optical power instability in complex environments, and by amplifying narrow pulses to provide higher output power to ensure that laser diodes output weakly coherent optical pulses and have a higher extinction ratio

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