Spectral investigation of Sm 3+ /Yb 3+ co-doped sodium telluriteglass

Sm3+/Yb3+ co-doped tellurite glasses are prepared by melt-quenching technique. The density of the glasses varies between 4.65 and 4.84 g/cm(3). The optical absorption spectra consist of eight bands in the wavelength range of 350-2 000 nm, which correspond to the transitions from ground level H-6(5/2) to the various excited states of the Sm3+ ion. Energy band gaps vary in the range of 2.73-2.91 eV, and the Urbach energy ranges from 0.21 to 0.27. Emission spectra exhibit four peaks originating from the (4)G(5/2) energy level centered at 576, 613, 657, and 718 nm. Quenches in emission bands may be due to the energy transfer from the Sm3+ to Yb3+ ions.