CW operation of a 1.3-μm strained quantum well laser on a graded InGaAs buffer with a GaAs substrate

We investigated MOVPE growth of 1.3 μm lasing SL-QWs with InGaP cladding layers on the compositionally graded InGaAs buffer layers with GaAs substrate. We found that the surface roughness of the lower InGaP layer causes generation of many dislocations around the SL-QWs. This deteriorated the photoluminescence intensity of the active layer. The surface roughness of the InGaP layers was reduced by the highly H₂ Se supply. The reduction of the surface roughness significantly suppresses the dislocations around the SL-QWs. This new technique realized the first CW-operation of the 1.3 μm SL-QW laser with InGaP cladding layers. We achieved a low threshold current of 15 mA and more than 15 mW output power