Empirical modeling of the refractive index for (AlGaIn)As lattice matched to InP

Abstract

A composition-dependent empirical interpolation formula for the refractive index of AlGaInAs epilayers lattice matched to InP substrate has been determined by using a reflection spectroscopy technique.The 2 μm thick (AlGaIn)As layers have been grown by MBE as well as MOVPE and were characterized by x-ray diffractometry and photoluminescence measurements.The measured data from these etalon structures were fitted by using a Sellmeier equation (single oscillator model) to retrieve the refraction index for wavelengths between 2.5 and 1 μm.The resulting accurate expression will be very useful for designing optoelectronic devices like VCSELs.