Accurate modelling of absorption and refractive index in a GaAs/AlGaAs quantum well

Using the real and imaginary dielectric constants of a GaAs/AlGaAs quantum well, both the absorption and refractive index of the structure were calculated. The imaginary dielectric constant was obtained by finding the contribution from each critical point in the density of states. The Kramers-Kronig transform of each contribution gave the corresponding real dielectric constant and these contributions were summed to give the material's total real dielectric constant. Absorption was found from the imaginary dielectric constant and fitted to experimental spectra. All contributions from confined and continuum transitions were considered in the subsequent calculation of refractive index with the resulting spectrum being comparable to published data.