Low-threshold operation of tensile-strained GaInP/AlGaInP MQW LDs emitting at 625 nm

A low threshold current of 47 mA at 20°C has been obtained in a tensile-strained index-guided AlGaInP LD emitting at 625nm, which has an active region consisting of five 8 nm-thick QWs with a lattice mismatch of −0.9%. It is shown that optimisation of the tensile-strained QW structure is very useful in improving the performance of AlGaInP LDs at wavelengths shorter than 630 nm.