Degenerate two-photon absorption spectra in Bi 2O 3:B 2O 3 glasses

Abstract

Degenerate two-photon absorption (TPA) spectra in binary xBi 2O 3:(100 − x)B 2O 3 ( x=60, 70 and 80 mol%) glasses are measured by an open-aperture Z-scan technique. The degenerate TPA coefficient, β, obtained at a fixed photon energy increases with Bi 2O 3 content (e.g., 12.8 ± 2.1 and 17.7 ± 3.0 cm/GW at 2.34 eV for x=60 and x=80, respectively), while β becomes larger at higher photon energy (e.g., 3.2 ± 0.5 cm/GW at 1.81 eV and 15.1 ± 2.5 cm/GW at 2.51 eV for x=70). The degenerate TPA spectra are reproduced by using a simple formula based on a two-parabolic band model for the electronic structure of the glasses containing heavy metal oxides.