光纤耦合周期极化铌酸锂薄膜波导器件的研究  

Study of Fiber-Coupled Periodically Poled Lithium Niobate Thin Film Waveguide Devices

作　　者：冯新凯[1,2] 陈怀熹 陈家颖[1,2] 梁万国 Feng Xinkai;Chen Huaixi;Chen Jiaying;Liang Wanguo(Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,Fujiang,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院福建物质结构研究所,福建福州350002 [2]中国科学院大学,北京100049

出　　处：《中国激光》2023年第22期118-123,共6页Chinese Journal of Lasers

基　　金：福建省中科院STS计划配套项目(2022T3012);中国福建光电信息科学与技术创新实验室(闽都创新实验室)自主部署项目(2021ZZ104)。

摘　　要：对硅基周期极化铌酸锂(PPLN)薄膜脊形波导进行了理论分析,并使用有限元软件模拟了25℃下泵浦波长为1560 nm的PPLN脊形波导的准相位匹配(QPM)周期与波导脊高和脊宽的关系。仿真结果表明,在相同脊宽(10μm)或脊高(10μm)下,PPLN脊形波导的QPM周期随着脊高或脊宽的增加而增大,最后趋于常数(即块状PPLN的QPM周期)。进一步模拟了在脊高和脊宽维持不变的情况下,PPLN脊形波导的QPM周期与温度之间的关系。结果表明,随着温度的增加,PPLN脊形波导的QPM周期逐渐减小,并且温度每升高1℃,QPM周期减小约3 nm。根据仿真结果制作了硅基片上集成PPLN脊形波导器件,将其封装成小体积的光纤入光纤出的波导,并测试了性能。当温度为24.8℃、1560 nm基频光输入功率为1.2 W时,最大输出653 m W的倍频光,光光转换效率达54.4%,归一化转换效率为20.2%·W^(-1)·cm^(-2)。Objective Periodically poled lithium niobate(PPLN)is an excellent nonlinear crystal for laser wavelength conversion.Conventional nonlinear crystals typically require high peak pulse power input.However,because of its periodic non-critical phase matching characteristics,PPLN has high conversion efficiency.It is extremely suitable for continuous wave(CW)laser wavelength conversion and widely used in CW laser systems.In addition,PPLN can realize full-color laser output by flexibly designing its quasi-phase matching(QPM)period,which has strong practical value.There has recently been a gradual shift from bulk PPLN to PPLN thin-film optical waveguides to improve the nonlinear frequency conversion efficiency of CW lasers.In recent years,many domestic research institutions,such as Nanjing University,East China Normal University,Shandong University,and the Chinese Academy of Sciences,have conducted in-depth detailed research on the preparation and application of PPLN thin film optical waveguide devices.Nonlinear frequency conversion devices based on PPLN waveguides have been used in various applications,such as optical communication,quantum optics,microwave optics,and spectroscopy.As applications continue to grow,new requirements are set for the volume and portability of waveguides.This study briefly introduces the basic structure and principle of a silicon-based PPLN thin film ridge waveguide,and a commercially available compact fiber-in-fiber-out PPLN waveguide package module is designed and fabricated.Methods The fabrication process of the silicon-based PPLN thin-film ridge waveguide is as follows.First,a Z-cut lithium niobate wafer(0.5 mm thick)doped with MgO is poled at high voltage.According to the FDTD software analysis results,the poled period is chosen to be 18.7μm to obtain phase matching of the pump wavelength near 1560 nm.After poling,a silicon dioxide buffer layer with a thickness of approximately 600 nm is deposited on one side of the PPLN wafer,subsequently,a gold layer of approximately 300 nm thickness is

关 键 词：非线性光学 周期极化铌酸锂 薄膜 准相位匹配 脊形波导 

分 类 号：O437[机械工程—光学工程]