全光纤量子保密通信关联光子对产生实验研究

Two experimental schemes of generating correlated photon-pair with nonlinear dispersion shifted-fiber and distributed-feedback laser are proposed in this project. The first scheme is to use the dual-wavelength laser to pump the high nonlinear dispersion-shifted fiber. It causes non-degenerated Four-wave mixing process in zero dispersion zone and generate correlated photon-pair; the second scheme is to inject the external probe into the distributed-feedback laser cavity to cause non-degenerated four-wave mixing process and generate correlated photon-pair. Comparing the features of two setup and acquire high quality correlated photon pair. Meanwhile, the spectral of photon pair ,the entanglement nature and the efficiency of producing photon-pair are experimentally investigated. In this way we can acquire high quality correlated photon-pair and realize the all-fiber C-band heralded single photon source output. The advantage of the correlated photon-pair generated by this project is that: single photon source can be inserted into the existing optical fiber communication network; the all- fiber pure waveguide mode can ensure the photon transmitted in a single spatial mode; single photon source has high coupling efficiency with fiber and the wavelength of single photon source is in optical communication C-band with the minimum transmission loss. It is helpful for the realization of long distance quantum security communication.

本项目提出利用非线性色散位移光纤和分布反馈激光器二种方案产生关联光子对实验研究，其中，第一种方案是用双波长激光泵浦高非线性色散位移光纤。在零色散区发生非简并四波混频过程，产生关联光子对；第二种方案是用外部注入探测光，在分布反馈激光器腔内发生非简并四波混频过程，产生关联光子对。并比较两种方案的优缺点,从而获得高质量量子关联光子对。再对产生的关联光子对的频谱特性，量子纠缠特性，以及产生效率开展实验研究，探索影响产生关联光子对的主要因素。本项目产生关联光子对的优势在于：单光子源可以直接嵌入到现有的光纤通信网络中，全光纤、纯净的波导模式能够保证传输的光子为单一的空间模式；单光子源与光纤的耦合效率高，而且单光子的波长在光通讯的波段，传输损耗最小，有利于长距离量子通信的实现。

本项目提出和研究了利用非线性色散位移光纤和分布反馈激光器二种方案产生关联光子对实验，其中，第一种方案是利用双波长激光泵浦高非线性色散位移光纤，在零色散区，发生非简并四波混频过程，产生关联光子对；第二种方案是用外部注入探测光，在分布反馈激光器腔内发生非简并四波混频过程，产生关联光子对。并比较两种方案的优缺点，从而获得高质量关联光子对。并对产生的关联光子对的频谱特性，量子纠缠特性，以及产生效率进行了实验研究，得到了影响产生关联光子对的主要因素。本项目产生关联光子对的优势在于：关联光子对可以直接嵌入到现有的光纤通信网络中，全光纤、纯净的波导模式能够保证处传输的光子为单一的空间模式；但光子源与光纤的耦合效率高，而且但光子源的波长在光通信的波段，传输损耗最小，有利于长距离量子通信的实现。