Optical properties and laser applications of (InGa)As/(AlGa)As self-assembled quantum dots

We study the photoluminescence and laser properties of (InGa)As/(AlGa)As se lf-assembled quantum dots (QDs). By varying the Al content in the (AlGa)As matrix and/or stacking several QD layers, the room temperature dot luminesc ence is tuned over a wavelength range from 0.8 mum to 1.3 mum. In particula r, by embedding the (InGa)As QD layer in a GaAs/AlGaAs quantum well, an hig h temperature light emission from the dots can be obtained (up to 500 K). W e also study the properties of QD lasers and show that both cavity effects and thermal coupling between dots play an important role in determining the QD laser emission.