近红外铌酸锂光栅耦合器耦合效率优化研究  

Research on optimization of the coupling efficiency of near-infrared lithiumniobate grating coupler

作　　者：刘思琦 瞿敏妮 谢微 LIU Siqi;QU Minni;XIE Wei(State Key Laboratory of Precision Spectroscopy,East China Normal University,Shanghai 200241,China;Center for Advanced Electronic Materials and Devices,School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong University,200240,China)

机构地区：[1]华东师范大学精密光谱科学与技术国家重点实验室,上海200241 [2]上海交通大学电子信息与电气工程学院先进电子材料与器件平台,上海200240

出　　处：《华东师范大学学报（自然科学版）》2024年第3期113-120,共8页Journal of East China Normal University(Natural Science)

基　　金：国家自然科学基金(12174112,62105199)。

摘　　要：提出了一种基于铌酸锂导模结构的高效光栅耦合器设计方案及其优化的光学激发配置.利用有限时域差分算法对光栅耦合器的耦合效果进行了数值分析;主要研究了光栅周期、光栅占空比、二氧化硅隔离层厚度,以及入射光的偏振和角度对光栅耦合效率的影响;对在共振波长和非共振波长处空间光传播电场图像进行了模拟.理论仿真结果显示,在光栅周期为650 nm、光栅占空比为0.3、刻蚀深度为130 nm时,利用横磁(transverse magnetic,TM)偏振光沿光栅法线夹角17°方向入射,可获得优化的光栅耦合效率~38%,从而有效地将空间光耦合进入铌酸锂亚波长波导薄膜中,这对铌酸锂微纳光栅耦合器的设计和性能应用有借鉴和参考价值.We propose an efficient grating coupler design scheme based on a lithium niobate guided mode structure and its optimized optical excitation configuration.The coupling effect of the grating coupler is numerically analysed using the finite time domain difference algorithm.We study the effects of the grating period,grating duty ratio,silica isolation layer thickness,polarization and angle of incident light on the coupling efficiency of the grating.The spatial light propagation electric field images are simulated for resonant and non-resonant wavelengths.The results show that with a grating period of 650 nm,a grating duty cycle of 0.3 and an etching depth of 130 nm,an optimised grating coupling efficiency of~38%can be obtained using TM(transverse magnetic)polarised light incident along the grating normal angle of 17°,thus effectively coupling spatial light into the lithium niobate subwavelength waveguide film.This is of great reference value for the design and application performance of LiNbOg micro-nano grating couplers.

关 键 词：铌酸锂薄膜 导模共振 光栅耦合器 耦合效率 

分 类 号：O439[机械工程—光学工程]