基于光子晶体光纤的纯态单光子源及其在量子干涉中的应用

项目名称： 基于光子晶体光纤的纯态单光子源及其在量子干涉中的应用

项目编号： No.11304222

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 崔亮

作者单位： 天津大学

项目金额： 30万元

中文摘要： 纯态单光子在量子计算、量子测量等以独立光源间光量子干涉为基础的量子信息技术中具有重要的应用。宣布式单光子源基于非线性介质中自发参量过程所产生的关联光子对，是一种简便有效的单光子制备途径；而且，若自发参量过程由脉冲光泵浦且满足特定的相位匹配条件时，可直接高效率地产生宣布式纯态单光子。在诸多非线性介质中，光子晶体光纤具有色散可控、非线性高、空间传输模式好等优点，是制备纯态单光子源的理想介质之一。然而，在目前已有的利用光子晶体光纤产生纯态单光子的实验中，单光子源的态纯度受限于光纤的结构不均匀性，且其泵浦源均采用较为复杂和昂贵的钛宝石激光器。本项目拟通过对光子晶体光纤进行测量、分析和优化重组，消除其不均匀性的影响，以提高单光子源的纯度；并且拟采用自制掺镱光子晶体光纤飞秒激光器作为泵浦源，以促进单光子源的小型化。项目的目标是研制出高质量、小型化的宣布式纯态单光子源，并进一步研究其在量子干涉中的应用。

中文关键词： 宣布式单光子源；量子纯态单光子；光子晶体光纤；量子干涉；自发四波混频

英文摘要： Single photons with pure quantum state are highly desirable in quantum information technologies relying on the quantum interference between photons from independent sources, such as quantum computing and quantum metrology. The heralded single photon source, which is based on the correlated photon pairs produced form spontaneous parametric processes in nonlinear media, is a convenient and effective way for single photon generation; moreover, single photons can be heralded in pure quantum state directly and efficiently when the parametric process is pumped by ultrafast pulses and certain phase matching condition is fulfilled. Among the various kinds of nonlinear media, the photonic crystal fiber is identified as one of the most suitable media for the generation of pure state single photons, because it has many unique merits, such as controllable dispersion, high nonlinearity, and excellent spatial mode. However, in the demonstrated experiments of generating pure state single photons by photonic crystal fiber, the purity of the sources are restricted by the structural inhomogeneity of the fiber, and all the sources employ Ti:sapphire lasers as the pump source, which are complicated and costly. This research program intends to eliminate the influence of fiber inhomogeneity and improve the purity of the photonic crys

英文关键词： Heralded single photon source；Single photon with pure quantum state；Photonic crystal fiber；Quantum interference；Spontaneous four wave mixing