用MOCVD方法生长制备了多层InGaAs/GaAs量子点结构,并研制出量子点激光器.研究了多层量子点激光器阈值激射特性与量子点有源区结构之间的关系,结果表明激光器的阈值电流密度依赖于量子点的结构.通过采用多层量子点、对量子点层间进行耦合以及采用宽禁带AlGaAs作为量子点层势垒可以有效地降低激光器的阈值电流密度.获得了最低为20 A/cm2的平均阈值电流密度.量子点激光器的激射波长也与有源区结构有关,随着量子点层数增加,激射峰向长波方向移动.

In this work, InGaAs/GaAs multi-layers quantum dots are grown by using MOCVD technique and ridge-like stripe structures are fabricated. It is shown that the threshold current density is dependent on the QDs structure. The threshold current density is greatly lowered by using multi-layers quantum dots, coupled QDs layers and wide band gap barriers. The minimum average threshold current density of 20 A/cm 2 is achieved. The lasing wavelength is also dependent on the active region. With increasing the number of QDs layers, the lasing peak will move to long wavelength end.