Parametrization of the Forouhi–Bloomer–Lorentz model for Ta_2O_5 films in the fundamental-absorption region

Abstract

The complex optical and dielectric functions of the energy of an electromagnetic wave are calculated for a film of tantalum (V) oxide in the short-wavelength region, including the fundamental-absorption region. An additive combination of the Forouhi–Bloomer and Lorentz models is constructed to compute these functions. Versions of the Forouhi–Bloomer model with a dipole-transition matrix element that is independent of the wave energy are considered, along with a modified model. It is established that the modified model has an advantage when describing broad-band dielectric amorphous media. The optical band gap computed from the Forouhi–Bloomer and Lorentz models is compared with the value determined from the Tautz extrapolation.