Photoreflectance and reflectance investigation of deuterium-irradiated GaAsN

The effect of deuterium irradiation on the optical and strain properties of GaAsN/GaAs heterostructures was investigated by photoreflectance and reflectance techniques. The strain occurring in as-grown and deuterated GaAsN layers is monitored and measured by means of photoreflectance spectroscopy, highlighting the strain inversion after irradiation. By combining static and modulated reflectance results, evidence is given that the deuterium-induced recovery of the GaAs band gap as well as the strain inversion in GaAsN layers are accompanied by a 0.4%-0.8% reduction of the refractive index in the 1.31 and 1.55 mu m spectral windows of interest for fiber optic communications. These results anticipate a single step process to an in-plane confinement of carriers and photons. (c) 2007 American Institute of Physics.