905 nm多有源区半导体激光器芯片结构优化设计  

Chip Structure Optimization of 905 nm Multiple-Active-Region Semiconductor Lasers

作　　者：姬世宇 熊聪[1] 祁琼[1] 常津源 李伟[1] 刘素平[1] 马骁宇[1] Ji Shiyu;Xiong Cong;Qi Qiong;Chang Jinyuan;Li Wei;Liu Suping;Ma Xiaoyu(National Engineering Research Center for Optoelectronic Devices,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;School of Electronic,Electrical and Communication Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院半导体研究所光电子器件国家工程研究中心,北京100083 [2]中国科学院大学电子电气与通信工程学院,北京100049

出　　处：《光学学报》2023年第13期171-176,共6页Acta Optica Sinica

基　　金：中国科学院战略性先导科技专项(B类)(XDB43030301);国家自然科学基金(62174154)。

摘　　要：905 nm多有源区激光器主要用作车载激光雷达的信号源。为了进一步降低激光器的阈值电流、提高斜率效率,对激光器芯片结构进行优化。在非对称大光腔波导外延结构的三有源区激光器中引入隔离沟道结构,通过控制隔离沟道的刻蚀深度和间距来抑制电流的横向扩散效应,提升器件性能。所制备的腔长为1 mm、电极宽度为110μm、沟道刻蚀深度为7.0μm,间距为125μm的三有源区器件,能够将阈值电流降低到0.64 A,得到3.58 W/A的斜率效率,并在0.1%电流脉冲占空比的工作条件下获得134 W的峰值功率。Objective 905 nm multiple-active-region lasers are mainly employed as the signal source of vehicle lidars.By alternately growing lasers and tunnel junctions on the same epitaxial wafer,lasers will be cascaded in the same structure by the quantum tunneling effect of tunnel junctions.However,the heavily doped tunnel junction(about 1×10^(20) cm^(-3))leads to rather low resistance,and then the lateral expansion of current will increase here,causing more unnecessary heat loss.At the same time,the current injected into different active regions decreases successively,and it is more difficult to emit the next active region.This increases the threshold current of the device and even leads to the impossibility to emit the lasers.In the conventional laser process,the method of isolation channel is often adopted to suppress the lateral expansion of current.However,the conventional process is mainly aimed at lasers with single active regions,and it employs wet etching with shallow etching depth and low precision.We introduce the isolation channel into the structure of multipleactive-region lasers,and simulate and calculate the lateral current density at different positions.Based on the calculated results,the isolation channel with different depths and spacing is designed,and the device is made and tested to study the suppression effect of different structures on the lateral current and optimize the chip structures.Methods The layer stack grown on a GaAs substrate by metalorganic vapor phase epitaxy consists of n-Al_(0.4)Ga_(0.6)As cladding(donator density ND=1×10^(18) cm^(-3)),p-Al_(0.45)Ga_(0.55)As cladding(acceptor density NA=2×10^(18) cm^(-3)),n-and p-Al_(0.3)Ga_(0.7)As optical confinement layers without doping around the active regions and tunnel junctions.The two In_(0.08)Ga_(0.92)As quantum wells sandwiched between Al_(0.3)Ga_(0.7)As spacer layers are the active regions.The two GaAs TJs are placed between diodes for cascading.An asymmetric large cavity structure with thick n side is designed.By increasing the thickne

关 键 词：激光器 半导体激光器 隔离沟道 电流横向扩散 隧道级联 

分 类 号：TN248.4[电子电信—物理电子学]