Variation of refractive index in strained In<i>x</i>Ga1−<i>x</i>As-GaAs heterostructures

Abstract

InxGa1−xAs-GaAs heterostructures and strained-layer superlattices can be used as optical waveguides. For such applications it is important to know explicitly the refractive index variation with mismatch strain and with alloying in the ternary layer. Starting from the Kramers-Kronig integral dispersion relations, we have developed a model from which the refractive index change in the ternary layer of InxGa1−xAs-GaAs heterojunctions can be calculated. The results are presented and discussed. The expected changes in a superlattice have been qualitatively predicted.