Wide operating wavelength range and low threshold current In/sub 0.24/Ga/sub 0.76/As/GaAs vertical-cavity surface-emitting lasers

Very low threshold current density operation of triple quantum well vertical-cavity surface-emitting lasers (VCSELs) is reported. The active wells are strained In/sub 0.24/Ga/sub 0.76/As 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/sup -2/ at 1018 nm. The dependence of threshold current on wavelength gives an insight into the optical gain spectrum of the quantum wells. It was shown that 50- mu m-diameter devices operate CW without heatsinking.>