Optical Properties of Erbium Doped Bismuth Tellurite Glasses

Erbium doped bismuth tellurite glasses, 85TeO(2)-(15 - x)Bi2O3-xEr(2)O(3) (where x = 0.1, 0.2, 0.3, 0.4 and 0.5 mol%) have been prepared by conventional melt quenching technique and their Optical properties were investigated through UV-Visible spectrophotometer. The optical absorption spectra were recorded at room temperature in the wavelength range from 200 to 1100 mm. From the absorption edge data, it is found that the both direct and indirect transitions and their values are ranging from 2.23 to 2.73 eV and 1.57 to 2.37 eV respectively and Urbach energy of the glasses was determined. The parameters density, molar volume, refractive index and polarizability of oxide ions have also been determined and their variations have been discussed with respect to erbium concentration. The Fourier transform infrared (FTIR) spectral studies shows the bonding of the glass system.