Investigation of spectral output of Er 3+ and Yb 3+ /Er 3+ doped TeO 2 –ZnO–BaO glasses for photonic applications

Er 3+ and Yb 3+ /Er 3+ doped TeO 2 –ZnO–BaO glasses were synthesized using the melt quenching technique with two different Er 3+ concentrations. The refractive index was calculated to be around 2.14 from the optical band gap energies of the glasses. Under 975 nm laser excitation, weak blue, strong green and red emissions were observed in the visible region, while broadband emission around 1530 nm was recorded in the near infrared region. The increase in red emission intensity as a result of energy transfer from Yb 3+ ions to Er 3+ ions in Yb 3+ /Er 3+ co-doped glasses is clearly reflected in the change in color coordinates. The temperature sensing abilities of the glasses were determined from the intensity ratios of light emitted from thermally coupled energy levels ( 2 H 11/2 and 4 S 3/2 ) of Er 3+ ions. The highest absolute sensitivity was determined as 0.0046 K −1 at 453 K for Er 3+ doped glass and 0.0067 K −1 at 353 K for Yb 3+ /Er 3+ co-doped glass. These results show that Er 3+ and Yb 3+ /Er 3+ doped TeO 2 –ZnO–BaO glasses are promising candidates for both lighting and optical temperature sensors.