椭圆氧化孔径垂直腔面发射激光器的偏振特性  

Polarization Characteristics of Vertical Cavity Surface Emitting Laser with Elliptical Oxidation Aperture

作　　者：谢中华 渠红伟 周旭彦[2,3] 张建心 隋佳桐 孟凡胜 宫凯 郑妹茵 王海玲 王宇飞 齐爱谊[2,3] Xie Zhonghua;Qu Hongwei;Zhou Xuyan;Zhang Jianxin;Sui Jiatong;Meng Fansheng;Gong Kai;Zheng Meiyin;Wang Hailing;Wang Yufei;Qi Aiyi(School of Physics and Physical Engineering,Qufu Normal University,Jining 273165,Shandong,China;Weifang Academy of Advanced Opto-Electronic Circuits,Weifang 261000,Shandong,China;Laboratory of Solid State Optoelectronics Information Technology,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;School of Physics and Electronic Information,Weifang University,Weifang 261061,Shandong,China)

机构地区：[1]曲阜师范大学物理工程学院,山东济宁273165 [2]潍坊先进光电芯片研究院,山东潍坊261000 [3]中国科学院半导体研究所固态光电信息技术实验室,北京100083 [4]潍坊大学物理与电子信息学院,山东潍坊261061

出　　处：《中国激光》2024年第6期57-66,共10页Chinese Journal of Lasers

基　　金：山东省重点研发计划(2022CXGC02104);山东省重点研究开发计划(2023ZLYS03);广东省重点领域研究开发项目(2020B090922003)。

摘　　要：为了改善用于铷原子钟的795 nm垂直腔面发射激光器(VCSEL)的偏振稳定性,研究了不同氧化孔径和椭圆度对VCSEL偏振性能的影响。利用COMSOL Multiphysics的波动光学频域模块模拟了不同氧化孔径对有源区谐振光强的影响。结果表明,当氧化孔径为3.5~4.0μm时,有源区的谐振强度最高。采用可实时观察的湿法氧化系统,研究了氧化温度对氧化速率和氧化孔椭圆度的影响。随着注入电流的增加,三种不同椭圆氧化孔的VCSEL表现出不同的模式特性、偏振特性和偏振角旋转特性。测试结果表明,带有长轴径为3.7μm、椭圆度为1.7的椭圆氧化孔的VCSEL性能最佳。在85℃下,当注入电流为1.5 mA时,输出功率为0.86 mW,激光波长为795.4 nm,边模抑制比(SMSR)为43 dB,线宽为65 MHz,正交偏振抑制比(OPSR)为23.8 dB。在0.6~2.7 mA的范围内,VCSEL的主偏振方向保持不变。Objective A 795 nm vertical cavity surface emitting laser(VCSEL)has the advantages of a low threshold current,single-mode operation,a low power consumption,and high temperature and reliability.It is an ideal light source for quantum precision measurement in devices such as atomic clocks,atomic magnetometers,and atomic gyroscopes.A VCSEL typically uses oxidation limiting structures for mode regulation to achieve electro-optic confinement.A VCSEL with conventional circular oxide apertures has an axisymmetric structure,making it difficult to achieve polarization control in two orthogonal directions and prone to polarization instability with increasing current.The application of a VCSEL in a device such as a chip-level atomic clock requires it to have a stable polarization direction and high polarization suppression ratio.Asymmetric oxidation apertures are introduced to improve the polarization stability of the 795 nm VCSEL used for rubidium atomic clocks.Controlling the oxidation conditions such as the temperature and gas pressure in the wet oxidation process makes it possible to fabricate VCSELs with different oxidation rates and ellipticity values for their apertures and analyze the effects of these on the polarization performance,which assists in achieving a low threshold and high polarization output.Methods A two-dimensional cold-cavity simulation of a 795 nm VCSEL is conducted using the fluctuation optical frequency domain module in COMSOL Multiphysics,and the effects of different oxidation apertures on the resonant light intensity in the active region are simulated.The influence of the oxidation furnace temperature on the oxidation rate and ellipticity is studied using a real-time monitoring wet oxidation system and controlling oxidation parameters such as the temperature and gas pressure in the wet oxidation process.The ellipticity and aperture parameters are obtained by the ellipse fitting of the captured oxidation aperture images.Three types of VCSELs with different long-axis diameters and ellipticity value

关 键 词：激光器 垂直腔面发射激光器 氧化孔径 湿法氧化 正交偏振抑制比 窄线宽 

分 类 号：TN248.4[电子电信—物理电子学]