基于薄膜铌酸锂的模式色散相位匹配单光子源  

Mode-dispersion phase matching single photon source based on thin-film lithium niobate

作　　者：余桂芳 李志浩 肖天琦 冯田峰 周晓祺 Yu Gui-Fang;Li Zhi-Hao;Xiao Tian-Qi;Feng Tian-Feng;Zhou Xiao-Qi(State Key Laboratory of Optoelectronic Materials and Technologies,School of Physics,Sun Yat-Sen University,Guangzhou 510006,China;Hefei National Laboratory,Hefei 230088,China)

机构地区：[1]中山大学物理学院,光电材料与技术国家重点实验室,广州510006 [2]合肥国家实验室,合肥230088

出　　处：《物理学报》2023年第15期75-82,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61974168);广东省重大科技专项计划(批准号:2018B030329001,2018B030325001)资助的课题.

摘　　要：薄膜铌酸锂光学芯片因低损耗、高非线性系数及高电光调制带宽等特性,有望成为开展集成光学量子信息研究的理想实验平台.然而,到目前为止,基于薄膜铌酸锂的单光子源普遍采用周期性极化准相位匹配技术,该技术要求精确地制备电极并对铌酸锂波导进行周期性极化,工艺复杂且对加工精度要求较高.本文提出了一种基于模式色散相位匹配的薄膜铌酸锂单光子源器件.该器件无需制作电极,具备加工简便和集成度更高的优势,同时单光子产率可达3.8×10^(7)/(s·mW),能够满足光学量子信息处理的需求.此器件有望替代传统准相位匹配单光子源,进一步推动基于薄膜铌酸锂芯片的光学量子信息研究的发展.In the domain of integrated quantum photonics,the burgeoning superiority of lithium niobate’s secondorder nonlinearity in electro-optic modulation makes thin-film lithium niobate a leading quantum photonic platform after silicon.To date,single-photon sources using thin-film lithium niobate has mainly adopted periodic polarization quasi-phase matching technology,which requires the preparation of complex electrodes for domain inversion in the waveguide to realize quasi-phase matching.This method inevitably introduces complexity,such as complex processing methods,enlarged polarization regions,and compromised integration density.With the development of quantum information technology,the ever-increasing degree of integration constantly creates new demands.Consequently,the development of a streamlined,high-efficiency quantum light source on a lithium niobate platform is a pressing issue.In this study,we propose a novel thin-film lithium niobate parametric down-conversion single-photon source based on mode dispersion phase matching theory.The strategy is different from conventional strategies that utilize periodic polarization to generate single-photon sources in thin-film lithium niobate devices.In contrast to traditional quasi-phase matching techniques that utilize the phase matching between pump fundamental mode light and parametric fundamental mode light,our method employs the phase matching between the pump light’s higher-order mode and the parametric light’s fundamental mode.The pump light’s higher-order mode is obtained by designing an asymmetric directional coupler.The device’s single-photon yield can attain3.8×10^(7)/(s·mW),satisfying the requirements for optical quantum information processing.This innovative solution is expected to replace the traditional quasi-phasematching single-photon sources,thus further promoting the study of optical quantum information based on thin-film lithium niobate chips.

关 键 词：单光子源 薄膜铌酸锂 模式色散相位匹配 

分 类 号：TN40[电子电信—微电子学与固体电子学] O431.2[机械工程—光学工程] TB383.2[理学—光学]