The intensity of Raman scattering in glasses containing heavy metal oxides

Exceptionally high Raman intensities have been observed in glasses containing major amounts of Tl 2O, PbO, Bi 2O 3, and / or Sb 2O 3 in combination with GeO 2, SiO 2, and / or As 2O 3. Raman peaks were more than 30× the strength of vitreous SiO 2 and 3× vitreous germania (based on spectra reduced to absolute zero and corrected for refractive index differences). The variation of peak intensities with composition were investigated in several systems and the observed variations were found to be consistent with calculations based on a theoretical approach developed by Lines and coworkers. Two compositions show particular promise for active fiber device applications: one based on Sb 2O 3·GeO 2, exhibiting a strong bridged anion mode with a frequency shift near 400 cm −1, and one based on Bi 2O 3·PbO·GeO 2·SiO 2, with a superposition of strong acoustic Raman heavy metal modes with a frequency shift near 140 cm −1.