Spectroscopic properties of new BaCl2-BaO-TeO2 tellurite glasses for fibre and integrated optics applications

We present results of the study of transmittance and Raman spectra in BaCl2-BaO-TeO2 glasses possessing intense spontaneous Raman scattering which are promising for the development of integrated and fibre stimulated Raman lasers. Compared with oxide-tellurite systems these glasses are found to be transparent in a wider wavelength range, from 350 nm to 6.5 μm. A band near 765 cm-1 is found to arise in the Raman spectra of the glasses with total BaO and BaCl2 content exceeding 30 mol%. The band turns out to be 70-80 times as intense as the main Raman band with maximum near 440 cm-1 in SiO2 glass. Quantum-chemical calculations of the structure and vibrational spectra of the glasses show that the 765 cm-1 band is caused mainly by vibrations of O3Te-O- and O2Te = O non-bridging oxygen atoms