850nm单模面发射分布反馈式激光器  

850 nm Single-Mode Surface-Emitting Distributed Feedback Lasers

作　　者：李南果 刘灿 张鹏斐 向敏文 汤宝 颜伟年 阚强[5] 陆巧银[1] 国伟华[1] Li Nanguo;Liu Can;Zhang Pengfei;Xiang Minwen;Tang Bao;Yan Weinian;Kan Qiang;Lu Qiaoyin;Guo Weihua(Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan 430074,Hubei,China;Ori-Chip Optoelectronics Technology Co.,Ltd.,Ningbo 315000,Zhejiang,China;College of Information Science and Electronic Engineering,Zhejiang University,Hangzhou 310058,Zhejiang,China;Accelink Technologies Co.,Ltd.,Wuhan 430074,Hubei,China;Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China)

机构地区：[1]华中科技大学武汉国家光电研究中心,湖北武汉430074 [2]宁波元芯光电子科技有限公司,浙江宁波315000 [3]浙江大学信息与电子工程学院,浙江杭州310058 [4]武汉光迅科技股份有限公司,湖北武汉430074 [5]中国科学院半导体研究所,北京100083

出　　处：《中国激光》2022年第12期93-104,共12页Chinese Journal of Lasers

基　　金：国家重点研发计划(2021YFB2800500);国家自然科学基金(61875066);集成光电子学国家重点实验室开放课题(IOSKL2020KF18)。

摘　　要：介绍一种新型的850 nm单模面发射分布反馈激光器(SEDFB)。采用浅脊波导表面光栅结构提供足够的光反馈,采用含λ/4相移的二阶光栅在实现面发射的同时获得单纵模特性。采用方形氧化孔径构成无源分布布拉格反射镜(DBR)—有源分布式反馈区(DFB)—无源DBR三段结构,从而减小电流注入的有源区体积,获得了与垂直腔面发射激光器(VCSEL)类似的低阈值特性。对于50μm有源区长度的SEDFB,其阈值电流为1.8 mA,当注入电流为6.5 mA时,SEDFB的边模抑制比(SMSR)高达47 dB。同时,该激光器在注入电流为9 mA的情况下获得了17 GHz的弛豫振荡频率。SEDFB实现了准圆形光斑的面发射输出,其远场光斑发散角的半峰全宽约为21°×26°。Objective Currently,the growing bandwidth demands of cloud services are accelerating the hyperscale expansion of data centers.850nm vertical-cavity surface-emitting lasers(VCSELs)are widely used in data centers owing to their high-cost performance and high power.However,current commercial VCSELs operate in the multitransverse mode,and their applications are limited to the short connections of a few hundred meters.Owing to reduced mode partition noise and modal dispersion,single transverse-mode VCSELs can transmit over long distances in multimode fiber.Furthermore,in multitransverse-mode VCSELs,high-order modes consume a large fraction of the injection current,resulting in low relaxation oscillation frequencies.Therefore,850nm single-mode surfaceemitting lasers are an urgent requirement in emerging hyperscale data centers to provide cost-effective,highbandwidth,and long-distance optical communication systems.This paper presents an 850nm single-mode surfaceemission distributed feedback(SEDFB)laser with a rectangular oxide aperture and a shallow etched surface grating.A threshold current of 1.8mA and a side-mode rejection ratio(SMSR)of 47dB are achieved.Methods A first-order grating is used to provide adequate optical feedback for the laser.A second-order grating is used to achieve upward diffracted light.Aλ/4phase-shift structure is used to achieve stable single longitudinal mode lasing.Moreover,the simulation calculation is used to optimize the material and thickness of each layer of the waveguide structure and the coupling coefficient of the grating while ensuring the light confinement factor in the active region.Large-area rectangular oxide apertures are designed to confine current injection.Furthermore,the laser chip is epitaxially grown using metal-organic chemical vapor deposition(MOCVD).Wet etching with a citric acid-hydrogen peroxide solution is used to etch surface GaAs.The reactive coupled plasma(ICP)is used to etch the waveguides and gratings.Using a high-temperature wet oxidation method,a rectangular o

关 键 词：激光器 半导体激光器 面发射激光器 分布反馈激光器 表面光栅 阈值电流 单模 

分 类 号：O436[机械工程—光学工程]