Extremely low threshold current strained InGaAs/AlGaAs lasers by molecular beam epitaxy

Abstract

Using solid source molecular beam epitaxy we have grown strained layer InGaAs/AlGaAs graded index separate confinement heterostructure lasers operating at 1.01 μm. For broad-area, uncoated Fabry–Perot devices with cavity lengths in excess of 3000 μm, the threshold current density is 56 A/cm2, a value which we believe to be the lowest ever reported for laser diodes in any materials system. The internal quantum efficiency for these lasers is 88%, while the materials losses are 1.8 cm−1.