The intensity of Raman scattering in glasses containing heavy metal oxides.

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