The dielectric function ε ≡ ε1 + iε2 has been determined for Al2O3 films prepared by electron beam evaporation, in the 5–50-µm wavelength range. The data were extracted from spectrophotometric recordings of transmittance and reflectance by use of a novel technique. Supplementary measurements were made of the refractive index for visible and near-infrared wavelengths and of the dielectric constant at 1 MHz. Kramers-Kronig analysis was employed to check the consistency of our results for ε1 and ε2.
© 1981 Optical Society of America
T. S. Eriksson, A. Hjortsberg, G. A. Niklasson, and C. G. Granqvist, "Infrared optical properties of evaporated alumina films," Appl. Opt. 20, 2742-2746 (1981)