A multiquantum barrier and graded-index separate confinement heterostructure are employed in a 1.55 mu m InAlGaAs multiquantum well laser to reduce the threshold current and temperature sensitivity. A characteristic temperature as high as 77K is measured between 25 and 75 degrees C for as-cleaved 1000 mu m-long uncoated devices. The degradation of slope efficiency in the same temperature range is less than 30%.
