基于亚波长光栅辅助定向耦合器的集成铌酸锂偏振分束器  

Integrated Lithium Niobate Polarization Beam Splitter Based on a Subwavelength Grating-Assisted Directional Coupler

作　　者：陈力 周旭东 袁明瑞 肖恢芙 田永辉 CHEN Li;ZHOU Xudong;YUAN Mingrui;XIAO Huifu;TIAN Yonghui(School of Physical Science and Technology,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学物理科学与技术学院,兰州730000

出　　处：《人工晶体学报》2024年第3期465-471,共7页Journal of Synthetic Crystals

基　　金：甘肃省自然科学基金重点项目(23JRRA1026);甘肃省自然科学基金在站博士后专项项目(23JRRA1126)。

摘　　要：绝缘体上铌酸锂(LNOI)是实现高速光子集成回路(PICs)的理想平台。通过充分利用铌酸锂(LN)的优势,LNOI平台能够实现高速电光和高效非线性光学集成器件。偏振分束器(PBS)作为分离和组合两种正交偏振光模式的关键无源器件之一,在实现片上偏振复用系统并提升光通信系统数据传输容量方面发挥着至关重要的作用。近年来,基于不同结构的PBS已经被成功实现,其中,基于亚波长光栅辅助定向耦合结构的PBS表现出优异的器件性能和紧凑的器件尺寸。本文基于氮化硅-铌酸锂异质集成的间接刻蚀方案,实现了一种亚波长光栅辅助定向耦合结构的高性能PBS。仿真结果表明,当波长在1500~1600 nm时,器件的偏振消光比均大于24.49 dB。实验数据进一步证实,当波长在1500~1580 nm时,器件偏振消光比均大于18.06 dB。Lithium niobate on insulator(LNOI)is an ideal platform for realizing high-speed photonic integrated circuits(PICs).By taking full advantage of LN,the LNOI platform enables high-speed electro-optic and efficient nonlinear optical integrated devices.The polarization beam splitter(PBS)is one of the key passive devices for separating and combining two orthogonal polarized modes,which is essential for realizing on-chip polarization multiplexing systems and enhancing the data transmission capacity of photonic communication systems.In recent years,PBS has been successfully implemented based on various structures.Among them,the PBS based on subwavelength grating-assisted directional coupling structure stands out due to its excellent device performance and compact size.In this paper,we present a high-performance PBS with a subwavelength grating-assisted directional coupling structure,realized through an indirect etching scheme of silicon nitride-lithium niobate heterogeneous integration.Simulation results show that the device achieves a polarization extinction ratio greater than 24.49 dB in the wavelength range of 1500 nm to 1600 nm.Experimental data further confirms that the polarization extinction ratio of the device is greater than 18.06 dB in the wavelength range of 1500 nm to 1580 nm.

关 键 词：薄膜铌酸锂集成光子学 氮化硅-铌酸锂 偏振调控器件 偏振分束器 亚波长光栅 定向耦合器 

分 类 号：TN256[电子电信—物理电子学] O78[理学—晶体学]