基于V形硅的薄膜铌酸锂波导模式转换器  

Lithium Niobate Waveguide Mode Converter Based on V-Shaped Silicon

作　　者：张程 徐银 董越 张博 倪屹[1,2] Zhang Cheng;Xu Yin;Dong Yue;Zhang Bo;Ni Yi(School of IoT Engineering,Jiangnan University,Wuxi 214122,Jiangsu,China;Institute of Advanced Technology,Jiangnan University,Wuxi 214122,Jiangsu,China)

机构地区：[1]江南大学物联网工程学院,江苏无锡214122 [2]江南大学先进技术研究院,江苏无锡214122

出　　处：《激光与光电子学进展》2024年第5期443-450,共8页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(62205129);江苏省自然科学基金(BK20200592);中央高校基本科研基金(JUSRP12024)。

摘　　要：模式转换器承担着波导基模到高阶模的转换任务,是片上多模光传输、模分复用传输的重要器件。基于薄膜铌酸锂平台,提出一种利用V形硅阵列的薄膜铌酸锂波导模式转换器,转换结构主要包括沿光传输方向排布的V形硅阵列,位于薄膜铌酸锂波导顶部。基于上述结构进行详细的设计与优化分析,在中心波长为1550 nm、转换长度仅为11μm的情况下,实现了输入TE_(0)模到输出TE_(1)模的高效转换。模式转换效率为96.8%,串扰为-28.6 dB,插入损耗为0.78 dB。进一步对转换结构进行横向扩展,实现了输入TE0模到输出TE_(2)模的高效转换。模式转换效率为91.3%,串扰为-14.3 dB,插入损耗为1 dB。若继续扩展,可获得其他高阶模。本器件及设计方法有望在薄膜铌酸锂波导多模光传输方向发挥优势,推动薄膜铌酸锂光子集成器件及回路的发展。Mode converter,achieving the mode conversion task from fundamental mode to higher-order mode,is a key component for the on-chip multimode transmission and mode division multiplexing transmission.Here,we propose an array of V-shaped silicon mode converter based on the thin film lithium niobate(TFLN)waveguide.The mode conversion structure is consisted of an array of V-shaped silicon,where it is deposited atop the TFLN waveguide.Based on such structure,we conduct detailed structural analyses and optimizations,where the required conversion length is only 11μm and the central wavelength is 1550 nm for the mode conversion from input TE_(0)mode to output TE_(1)mode.The mode conversion efficiency,crosstalk,and insertion loss are 96.8%,−28.6 dB,and 0.78 dB,respectively.We further extend the device structure and obtain the mode conversion from input TE0 mode to output TE_(2)mode in the same length,where the mode conversion efficiency,crosstalk,and insertion loss are 91.3%,−14.3 dB,and 1 dB,respectively.If we further extend the device structure,other higher-order modes can also be obtained.We believe the proposed device structure and scheme could benefit the multimode transmission for the TFLN waveguide and boost the development of photonic integrated components and circuits based on the TFLN platform.

关 键 词：集成光学 集成光器件 光波导 铌酸锂 微光学器件 

分 类 号：TN252[电子电信—物理电子学]