Broadband second-harmonic generation in thin-film lithium niobate microdisk via cyclic quasi-phase matching  

作　　者：朱杰夫 丁婷婷 孙雪芮 倪枫超 黎浩 刘时杰 郑远林 陈险峰 Jiefu Zhu;Tingting Ding;Xuerui Sun;Fengchao Ni;Hao Li;Shijie Liu;Yuanlin Zheng;Xianfeng Chen(State Key Laboratory of Advanced Optical Communication Systems and Networks,School of Physics and Astronomy,Shanghai Jiao Tong University,Shanghai 200240,China;School of Electronic and Electrical Engineering,Shanghai University of Engineering Science,Shanghai 201620,China;Shanghai Research Center for Quantum Sciences,Shanghai 201315,China;Collaborative Innovation Center of Light Manipulations and Applications,Shandong Normal University,Jinan 250358,China)

机构地区：[1]State Key Laboratory of Advanced Optical Communication Systems and Networks,School of Physics and Astronomy,Shanghai Jiao Tong University,Shanghai 200240,China [2]School of Electronic and Electrical Engineering,Shanghai University of Engineering Science,Shanghai 201620,China [3]Shanghai Research Center for Quantum Sciences,Shanghai 201315,China [4]Collaborative Innovation Center of Light Manipulations and Applications,Shandong Normal University,Jinan 250358,China

出　　处：《Chinese Optics Letters》2024年第3期118-122,共5页中国光学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.12074252,12192252,and 62022058);the National Key Research and Development Program of China(No.2022YFA1205101);the Shanghai Municipal Science and Technology Major Project(No.2019SHZDZX01-ZX06);and the Yangyang Development Fund。

摘　　要：Whispering-gallery-mode(WGM)microresonators can greatly enhance light-matter interaction,making them indispensable units for frequency conversion in nonlinear optics.Efficient nonlinear wave mixing in microresonators requires stringent simultaneous optical resonance and phase-matching conditions.Thus,it is challenging to achieve efficient frequency conversion over a broad bandwidth.Here,we demonstrate broadband second-harmonic generation(SHG)in the x-cut thinfilm lithium niobate(TFLN)microdisk with a quality factor above 107by applying the cyclic quasi-phase-matching(CQPM)mechanism,which is intrinsically applicable for broadband operation.Broadband SHG of continuous-wave laser with a maximum normalized conversion efficiency of~15%/m W is achieved with a bandwidth spanning over 100 nm in the telecommunication band.Furthermore,broadband SHG of femtosecond lasers,supercontinuum lasers,and amplified spontaneous emission in the telecommunication band is also experimentally observed.The work is beneficial for integrated nonlinear photonics devices like frequency converters and optical frequency comb generator based on second-order nonlinearity on the TFLN platform.

关 键 词：lithium niobate whispering-gallery mode broadband second-harmonic generation cyclic quasi-phase matching 

分 类 号：O437[机械工程—光学工程]