Abstract
A k. p theoretical study of the optical properties of GaInAs and strained GaInAs/GaAs alloys is presented in this study. The complex dielectric function and the refractive index as a function of indium content were calculated. A very good agreement between the predictions made and the experimental data was obtained. The critical point transitions, static dielectric functions and zero frequency values of the refractive index, n(0), were calculated, showing a strong dependence on the biaxial strain. Finally, the theoretical calculations of the dependence of n(0) on the band-gap energy predict, for unstrained alloys, a similar relationship to that proposed by Anani et al. The Ravindra model showed the best agreement with our predictions for strained alloys.