AlGaAs-GaAs-InGaAs strained layer laser structure with performance independent of AlGaAs layer quality

An AlGaAs-GaAs-InGaAs strained layer laser structure has been shown to have a low threshold current density which is independent of AlGaAs layer quality. This threshold invariance is attributed to the use of a large GaAs region outside the InGaAs well to reduce the effects of traps in the AlGaAs on the active region of the laser and was demonstrated by characterising identical structures grown by molecular beam epitaxy (MBE) under different AlGaAs growth conditions. These results should have strong implications for the reliability and manufacturability of such lasers and for the integration with electronic devices where low temperature growth is required.