WIDE OPERATING WAVELENGTH RANGE AND LOW THRESHOLD CURRENT IN0.24GA0.76AS GAAS VERTICAL-CAVITY SURFACE-EMITTING LASERS

We report very low threshold current density operation of triple quantum well vertical-cavity surface-emitting lasers (VCSEL's). The active wells are strained In0.24Ga0.76As in GaAs. Devices from the same wafer operate at room temperature over a wavelength range of 958-1042 nm, with a minimum threshold current density of 366 A . cm-2 at 1018 nm. The dependence of threshold current on wavelength gives an insight into the optical gain spectrum of the quantum wells. 50 mum diameter devices operate CW without heatsinking.