High-performance InAs/GaAs quantum dot laser with dot layers grown at 425℃

We investigate InAs/GaAs quantum dot(QD) lasers grown by gas source molecular beam epitaxy with different growth temperatures for InAs dot layers.The same laser structures are grown,but the growth temperatures of InAs dot layers are set as 425 and 500 ℃,respectively.Ridge waveguide laser diodes are fabricated,and the characteristics of the QD lasers are systematically studied.The laser diodes with QDs grown at 425℃ show better performance,such as threshold current density,output power,internal quantum efficiency,and characteristic temperature,than those with QDs grown at 500 C.This finding is ascribed to the higher QD density and more uniform size distribution of QDs achieved at 425℃.     

外腔反馈对量子点激光器输出特性的影响

在对光栅外腔量子点激光器进行理论研究的基础上,分析了外腔反馈对Littrow型光栅外腔量子点激光器输出功率、调谐范围等输出特性的影响,发现器件参数的选择对外腔激光器的性能影响很大。对外腔激光器的输出功率和调谐范围进行了理论计算,并与实验结果进行了对比。计算得到的外腔激光器的输出功率与实验结果符合得很好,忽略了非线性增益相关的增益抑制的单模调谐范围理论计算值稍小于实验结果。