One- and two-photon absorption in transition metal oxide glasses

Scaling of nonlinear two-photon absorption to optical bandgap (which describes the electronic structure of material) in transition metal glasses is given through a proposed empirical equation. A wide applicability of the relation is proven through the 21 studied glasses. The relationship between the calculated nonlinear absorption coefficient and the measured bandgap energy using Tauc’s parabolic band model is discussed in terms of electronic structure of constituent oxides, ionic polarizability, hyperpolarizability of cations, nonbridging oxygen bonds, and the cationic bond-length approach.