Research On Key Technology In Quantum Key Distribution

Cryptology is one of the oldest applied sciences in the world. With the fast development of computer technology, especially the presentation of the quantum computer, this kind of security is severely challenged. Quantum cryptography, which is a combination of quantum mechanics and cryptology, solves the dilemma of the classical cryptography and has been developed as one of the most popular information technologies in the world. The security of quantum cryptosystems is only guaranteed by the fundamental laws of quantum mechanics: the uncertainty principle and the non-cloning theorem, so we should not worry about eavesdropping when the quantum key distribution is operated in a public channel.The driver circuit of the phase modulaor which is the main contribution of this dissertation is one of the most pivotal technologies in quantum key distribution experiments. The "Plug & Play" system has better optics long-term stability than the "Two asymmetric Mach-Zehnder" system because of the automatically compensation of the polarization mode dispersion and phase shift. The driver of the phase modulator is the most important part in the "Plug & Play" system. We researched and developped the driver circuit located in "Alice" site using the pure hardware implementation based on MCU & CPLD and basically realized our research objective.We have also done some research works on the single-photon source based on quantum dots. This kind of single-photon source, which can seadily emit single photons, is a real one. Compared with the other single-photon sources, single-photon source based on quantum dots has larger oscillator strength, narrower spectral linewidth, higher photon yield, and better long-term stability. The single-photon source based on quantum dots is recognized as the most potential one.