808 nm宽条型激光器绝热封装改善慢轴光束质量（英文）

Improving Slow Axis Beam Quality of 808 nm Broad-area Laser Diodes with Adiabatic Package

为降低半导体激光器在慢轴方向的远场发散角,改善慢轴光束质量,本文提出了一种新型的绝热封装结构,可削弱激光器工作时因芯片横向温度不均而导致的热透镜效应,并基于傅里叶热传导方程,采用有限元分析软件ANSYS 18.0进行热特性仿真,利用Fineplacet贴片机对808 nm In0.1Ga0.73Al0.17As/Al0.37GaAs宽条形半导体激光器进行绝热封装,采用电荷耦合器件(CCD)图像采集分析法对其光束质量进行测量。实验结果表明采用绝热封装方式可减小慢轴发散角约40%,且慢轴发散角随工作电流变化更稳定,相对应的光参数积BPP和光束质量因子M2也随之降低约33%和30%,芯片横向(慢轴方向)与热沉接触宽度越小,绝热封装对慢轴光束质量改善效果越好。绝热封装中空气隙的引入使得激光器光电特性产生恶化,输出功率降低约14%,光电转换效率降低约8.7%。绝热封装方式对改善半导体激光器的慢轴光束质量具有重要的指导意义。

In order to reduce far-field divergence angle of semiconductor laser along slow axis and improve slow axis beam quality,a new type of adiabatic package structure is proposed.With this structure,the strength of thermal lens effect of the laser chip can be reduced.We have simulated the lateral heat distribution of broad-area semiconductor laser chip with the new structure by ANSYS 18.0,the model is based on the law of heat conduction(Fourier’s law).The beam quality of 808 nm In0.08 Ga0.78 Al0.14 As/Al0.37 Ga As broad-area semiconductor laser was experimentally investigated.Measurement is based on charge coupled device(CCD)image acquisition analysis method.The results show that the adiabatic package structure can reduce slow axis divergence angle by about 40%,and the slow axis divergence angle is more stable as the working currents change.Moreover,the corresponding beam parameter product(BPP)and beam quality factor M2 are also reduced by about 33%and 30%.The narrower the contact width between chip and heat sink is,the better the effect of the improvement will be.The introduction of the air gap in the adiabatic package leads to a deterioration of photoelectric characteristics.The output power P reduces by 14%,electro-optical conversion efficiencyηreduces by 8.7%.Adiabatic package method has guiding significance to the improvement of the slow axis beam quality of 808 nm broad-area semiconductor lasers.