基于SiO_(2)波导的低耦合系数、窄线宽、高阶布拉格光栅特性研究  

Characteristics of Low Coupling Coefficient,Narrow Linewidth,High Order Bragg Grating Based on SiO_(2)Waveguide

作　　者：尹小杰[1,2] 王警辉 郑之远 宋泽国 YIN Xiaojie;WANG Jinghui;ZHENG Zhiyuan;SONG Zeguo(State Key Laboratory of Integrated Optoelectronics,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;Henan Key Laboratory of Optoelectronic Circuit and Integration,Henan Shi Jia Photons Technology Co.,Ltd,Hebi 458030,China;Wuxi Institute of Interconnect Technology,Co.,Ltd,Wuxi 214000,China)

机构地区：[1]中国科学院半导体研究所集成光电子国家重点实验室,北京100083 [2]河南仕佳光子科技股份有限公司河南省光电芯片与集成重点实验室,鹤壁458030 [3]无锡芯光互连技术研究院有限公司,无锡214000

出　　处：《光子学报》2023年第4期281-290,共10页Acta Photonica Sinica

基　　金：国家重点研究发展计划(No.2019YFB2203004);中国计算机互联技术联盟基金项目(No.CCITA Funding 20220103)。

摘　　要：推导了布拉格光栅三维耦合系数公式,构建了一种新型的波导型布拉格光栅三维数值模型,并基于此设计制备出一种基于SiO2平面波导结构的低耦合系数、窄线宽、高阶布拉格光栅。从理论设计和试验验证两方面系统分析了布拉格光栅刻蚀深度及占空比对光栅耦合系数和线宽的影响,并最终设计制备出了中心波长为1554.053 nm,反射率为-8.5 dB,峰值半高宽为89 pm的SiO2波导结构布拉格光栅器件。本文设计制备的低耦合系数高阶布拉格光栅器件工艺简单,成本低,在滤波器、传感器及外腔窄线宽激光器领域中有广阔的应用前景。As an important frequency selective component,Bragg grating is widely used in the fields of lasers,sensors and filters.Especially in the field of narrow linewidth lasers,Bragg grating is an important component for narrowing the linewidth of lasers.The linewidth and reflectivity of Bragg grating itself have a decisive influence on the performance and reliability of narrow linewidth lasers.The narrower the linewidth of the Bragg grating itself is,the greater the mode competition between the cavity mode of the gain chip and the longitudinal mode of the grating will be improved,and the temperature stability of the wavelength will also be improved accordingly.In this paper,SiO_(2)waveguide material with low transmission loss was selected.The refractive index of the waveguide cladding was 1.4447,the refractive index of the core layer was 1.4556,and the refractive index difference was 0.75%.Using the single-mode condition simulation of the waveguide transmission mode,the cross-sectional size under the single-mode condition of the waveguide was calculated to be 6μm×6μm.Under this single mode condition,starting from the wavelength equation of Bragg grating satisfying Bragg reflection condition,the paper mainly analyzed the coupling between TE-TE modes.Through the derivation of the refractive index change formula and the normalization equation,the three-dimensional numerical model of the coupling coefficient of Bragg grating was finally deduced,and the coupling coefficient variation relationship corresponding to the change of the grating structure was simulated when the grating etching depth increases from 1μm to 6μm and the duty cycle increases from 0.5 to 0.8.On this basis,the paper also further analyzed the numerical relationship between the etching depth,duty cycle of waveguide Bragg gratings,the reflectivity and FWHM of the gratings,thus establishing a high-precision theoretical model for the design of waveguide Bragg gratings,and designing a series of waveguide Bragg grating devices under this model.The grating

关 键 词：平面光波导 二氧化硅 低耦合系数 高阶光栅 峰值半高宽 布拉格光栅 

分 类 号：TN2[电子电信—物理电子学]