Upconversion in Er3+-doped Bi2O3-Li2O-BaO-PbO tertiary glass

Radiative properties of Er3+-doped tertiary bismuth glass has been analyzed by the Judd-Ofelt theory. NIR to visible upconversion in the Er3+ doped glass has been reported. The mechanism for the upconversion is explained on the basis of quadratic dependence on excitation power and on the energy-matching scheme. Energy transfer is noted as the dominant process including the long-lived I-4(1/2) level as the intermediate state for the green and red upconversion emissions. The effect of temperature on the fluorescence intensity of the two bands due to H-2(1/2) -> I-4(15/2) and S-4(3/2) -> I-4(15/2) transitions as well as on the transitions due to Stark components of the S-4(3/2) level have been monitored and it is concluded that their intensity ratio may serve as better temperature sensing device. (c) 2006 Elsevier B.V. All rights reserved.