Ordinary and extraordinary refractive indices for AlxGa1-xN epitaxial layers

Dispersion of the ordinary and extraordinary indices of refraction for wurtzite AlxGa1-xN epitaxial layers with x=0.00, 0.04, 0.08, 0.11, and 0.20 in the range of wavelengths 457 <lambda < 980 nm were measured via a prism-coupled waveguide technique. The quantitative accuracy of x is +/- 10% and the accuracy of the refractive indices is +/-0.01. The dispersion is found to be well described by a 1st-order Sellmeier dispersion formula. A simple functional form is presented that allows calculation of the refractive indices as functions of x and lambda. (C) 1999 American Institute of Physics. [S0003-6951(99)04127-3].