用于量子纠缠密钥的多波长量子关联光子对的产生  

Generation of multiwavelength quantum correlated photon pair for quantum entanglement key distribution

作　　者：胡飞飞[1] 李思莹 朱顺 黄昱[1] 林旭斌 张思拓[1] 范云茹 周强 刘云 Hu Fei-Fei;Li Si-Ying;Zhu Shun;Huang Yu;Lin Xu-Bin;Zhang Si-Tuo;Fan Yun-Ru;Zhou Qiang;Liu Yun(Power Dispatching Control Center of China Southern Power Grid Co.,Ltd.,Guangzhou 510663,China;Anhui Quantum-Safe Engineering Technical Research Center,Wuhu 241002,China)

机构地区：[1]中国南方电网电力调度控制中心,广州510663 [2]安徽省量子安全工程技术研究中心,芜湖241002

出　　处：《物理学报》2024年第23期70-76,共7页Acta Physica Sinica

基　　金：中国南方电网有限责任公司科技项目(批准号:000005KK52220034(ZDKJXM20222036))资助的课题.

摘　　要：随着量子信息技术的发展,多用户量子纠缠密钥分发网络受到越来越多的关注.其中,多波长量子光源是建立多用户连接的关键器件.尽管近年来在多波长量子光源的研究上取得了显著的进展,但受限于非线性光学器件的设计和制备技术,增加量子光源的输出波长数仍然具有挑战性.本文系统分析了氮化硅微环谐振腔的色散和尺寸等关键参数;设计并制备得到了自由光谱范围为20 GHz的氮化硅微环谐振腔,实验测试了氮化硅微环腔中量子关联光子对的产生和输出特性.实验结果表明,该光源在25.6 nm的波长范围内实现了71对波长上的关联光子对产生.With the rapid development of quantum information technology,fully connected multi-user quantum entanglement distribution networks have received increasing attention.Among these,multi-wavelength quantum light sources are key devices for establishing connections between multiple users.Despite recent impressive advances,there are still challenges in increasing the wavelength number of photon pairs due to limitations in the design and fabrication of nonlinear optical devices.The potentials of silicon nitride(Si3N4)microring resonators(MRRs),as scalable platforms for multi-wavelength quantum light sources,are explored in this work.The key design parameters of the Si3N4 MRRs,including waveguide dimension,resonator dispersion,and coupling condition,are comprehensively analyzed to optimize photon-pair generation.Based on these parameters,a Si3N4 MRR with a free spectral range of 20 GHz and an average quality factor of 1.6 million is designed and fabricated.This small free spectral range can generate more channels of correlated photon pairs by using the same wavelength resources.The high-quality resonator contributes to the enhancement of the rate of generating high photon pairs,which are critical for quantum entanglement distribution.With a continuouswave pump laser,correlated photon pairs across a wide spectral range are generated through the spontaneous four-wave mixing(SFWM).The coincidence-to-accidental ratio(CAR)measurements verify the strong quantum correlation between photon pairs,highlighting the reliability of the system for entanglement distribution.Furthermore,the generation and output characteristics of quantum-correlated photon pairs are experimentally investigated with a tunable bandpass filter.The results demonstrate that 71 wavelength-correlated photon pairs within a 25.6 nm spectral range are successively generated as shown in the Fig.A.Our results pave the way for developing the multi-wavelength quantum light sources with Si3N4 platform,thereby advancing the multi-user quantum networks.

关 键 词：微环谐振腔 量子光源 量子关联 量子纠缠密钥 

分 类 号：O431.2[机械工程—光学工程] TN918.4[理学—光学]