Research On Experimental Quantum Key Distribution System Based On Optical Fiber

With the rapid development of information technology, the amount of informationshared between us through the network is growing, a lot of them Contain privacy.Quantum cryptography communication was proposed to to transmit Secret informationwhich can ensure unconditional safety. Based on the experiment, this paper research ondifferent scheme of quantum-bit coding and protocol, and then analyze problems of theexperiment.Firstly, the basic concept, current situation and prospect of quantum keydistribution are presented. Secondly, the QKD platform based onpolarization-encoding and B92scheme is discussed, in the sender the double delaycircuit is used to generate Narrow pulse, which can drive the laser to generate lightpulses. The light pulse then is attenuated to produce quasi-single-photon, then we canfulfill Quantum Key Distribution by modulating the Polarization of single-photon. Weanalyze the short of the experiment, and focus on the influence of Path-attack andperformance of Single-photon detector, then we propose the improved methods.Thirdly, QKD platform based on phase-encoding and BB84scheme is also discussed,we mainly present the design of the drive of intensity modulator and phase modulator.Then we pay attention to the mismatch problem of Single-photon detector, note theproblem of interferometer in stability and contrast, and propose some suggestion andmethods to solve.Finally, we review the paper and give some suggestion for futureworks.