Resonant enhancement of second harmonic generation in etchless thin film lithium niobate heteronanostructure

作     者：Zhijin Huang Kaiwen Luo Ziwei Feng Zhanyuan Zhang Yang Li Wentao Qiu Heyuan Guan Yi Xu Xiangping Li Huihui Lu 

作者机构：Guangdong Provincial Key Laboratory of Optical Fiber Sensing and CommunicationsDepartment of Optoelectronic EngineeringJinan UniversityGuangzhou 510632China Guangdong Provincial Key Laboratory of Optical Fiber Sensing and CommunicationsInstitute of Photonics TechnologyJinan UniversityGuangzhou 510632China Guangdong Provincial Key Laboratory of Information Photonics TechnologyInstitute of Advanced Photonics TechnologySchool of Information EngineeringGuangdong University of TechnologyGuangzhou 510006China 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2022年第65卷第10期

页      面：75-82页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 0804[工学-仪器科学与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 61775084, and 62075088) the National Safety Academic Fund (Grant No. U2030103) the Natural Science Foundation of Guangdong Province (Grant Nos. 2020A1515010791, and 2021A0505030036) the Open Fund of Guangdong Provincial Key Laboratory of Information Photonics Technology of Guangdong University of Technology (Grant No. GKPT20-03) the Fundamental Research Funds for the Central Universities (Grant Nos. 21622107, and 21622403) 

主　　题：second harmonic generation etchless thin-film lithium niobate heteronanostructure high-Q resonance 

摘      要：Lithium niobate has received interest in nonlinear frequency conversion due to its wide transparency window,from ultraviolet to mid-infrared spectral regions,and large second-order nonlinear ***,its nanostructure is generally difficult to etch,resulting in low-Q resonance and lossy nanostructures for second harmonic *** applying the concept of bound states in the continuum,we performed theoretical and experimental investigations on high-Q resonant etchless thin-film lithium niobate with Si O_(2) nanostructures on top for highly efficient second harmonic *** the fabricated nanostructured devices,a resonance with a Q factor of 980 leads to the strong enhancement of second harmonic generation by over 1500 times compared with that in unpatterned lithium niobate thin *** the pump slightly deviates from central resonance,an absolute conversion efficiency of 6.87×10^(-7) can be achieved with the fundamental pump peak intensity of 44.65 MW/cm^(2),thus contributing to the normalized conversion efficiency of 1.54×10^(-5)cm^(2)/*** work establishes an etchless lithium niobate device for various applications,such as integrated nonlinear nanophotonics,terahertz frequency generation,and quantum information processing.