碲酸盐光子晶体光纤产生高纯度量子关联光子对的研究

The generation of high-purity and high-efficiency quantum-correlated photon pairs is crucial to realize quantum information processing. Owing to its merits of adjustable geometric structures and dispersion characteristics, photonic crystal fibers are considered to be effective for the generation of high-efficiency quantum-correlated photon pairs. However, Raman scattering noise in fibers is a key factor that restricts on the purity increasing of the correlated photon pairs. In this proposal, we will carry out a study on generation of high-purity and high-efficiency quantum-correlated photon pairs using tellurite photonic fibers with a low Raman scattering noise. Firstly, we will investigate the effect of dopant composition ratio on Raman scattering noise, and reduce the noise by selecting a new material composition of tellurite material. Secondly, structure design and fabrication of the tellurite photonic crystal fibers will be carried out to achieve a small dispersion value with a high nonlinear coefficient at telecommunication wavelengths. Finally, we will set up a measurement system and choose the proper experimental parameters to obtain the high-purity quantum-correlated photon pairs, and determine the various factors that affect the generation process of quantum-correlated photon pairs. This project will provide a new approach to generation of high-purity quantum-correlated photon pairs, and promote a rapid development of quantum information processing technology.

高纯度和高亮度的量子关联光子对在量子信息处理技术中具有至关重要的作用。光子晶体光纤具有可调的结构和色散特性，已经成为获得高亮度量子关联光子对的有效手段。然而，拉曼散射噪声是限制光纤中量子关联光子对纯度提高的主要因素。本项目拟采用低拉曼散射噪声的碲酸盐光子晶体光纤，通过四波混频效应获得高纯度和高亮度的量子关联光子对。首先，通过探索低拉曼散射噪声的碲酸盐材料体系，揭示碲酸盐掺杂组分对噪声抑制的作用机制；其次，设计并拉制出高非线性的碲酸盐光子晶体光纤，使其具有色散平坦、零色散波长位于光通讯波段等特点；最后，建立量子关联光子对测量系统，合理选择泵浦光和滤波带宽等参数，获得高纯度的量子关联光子对，阐明影响高纯度量子关联光子对纯度的关键因素。本项目将为高纯度量子关联光子对的产生提供一种新研究思路，将促进量子信息处理技术的快速发展。

光子晶体光纤具有灵活可调的结构和色散特性，可以通过改变光纤包层与纤芯的几何结构，有效控制和调节非线性光学过程。碲酸盐光纤具有高非线性，且适于在中红外波段应用。目前如何利用光子晶体光纤的非线性获得量子关联光子对以及进行传感、滤波等功能器件的实现是亟待解决的问题。本项目实施以来，按照项目计划书开展了光子晶体光纤非线性性能的研究，完成了研究任务。取得的主要研究成果包括：对基于高非线性碲酸盐的四波混频、自相位调制等特性进行研究，获得很好的四波混频以及自相位调制效果；基于优异的四波混频性能进行传感器件的研究。通过探索低拉曼散射噪声的碲酸盐材料体系，揭示碲酸盐掺杂组分对噪声抑制的作用机制；设计并拉制出高非线性的碲酸盐光子晶体光纤，使其具有色散平坦、零色散波长位于光通讯波段等特点；利用碲酸盐光子晶体光纤的高非线性进行磁场、温度、折射率等传感器件的研究，我们的工作将光纤的非线性现象应用到光纤传感技术，并验证了色散波和孤子都可以用于实现高性能的光纤传感器。截止2021年12月，共计在Optics Express、IEEE Sensors Journal 等杂志发表SCI论文40余篇。本项目的顺利实施为制备高性能的光子晶体光纤器件提供了科学基础。