BAND-GAP BLUE-SHIFT BY IMPURITY-FREE VACANCY DIFFUSION IN 1.5-MU-M STRAINED-INGAASP INP MULTIPLE-QUANTUM-WELL LASER STRUCTURE/

The effects of defect-enhanced, impurity-free, quantum-well (QW)-barri er compositional intermixing caused by the SiO2 cap annealing at 750 d egrees C of a 1.5-mu m InGaAsP/InP multiple quantum-well (MQW) laser s tructure have been studied by photoluminescence (PL). A substantial ba nd-gap blue shift, as much as 112 nm (similar to 66 meV), was found in the structure and the value of the shift can be controlled by the ann eal time. The amount of the shift does not depend on the thickness of the SiO2 cap layer. Ridge-waveguide lasers were fabricated on the diff erent areas of the wafer, with and without a SiO2 cap during a 60 s an neal. The lasing wavelength of the laser produced with the SiO2 cap ha s a 78 nm blue shift over that of the laser without the SiO2 cap. (C) 1997 American Institute of Physics.