Spectroscopic characterization of erbium doped glass ceramic

Abstract

Erbium doped oxyfluoride glass was synthesized from the molar composition 10.1% Na2CO3 −20.2% PbO −33.7% GeO2 −33.6% TeO2 −2.4% ErF3 by melt quenching technique. The Judd-Ofelt intensity parameters were estimated as Ω2 = 10.8 × 10−20, Ω4 = 1.17 × 10−20, and Ω6 = 4.32 × 10−20 cm2. Radiative transition probabilities and lifetimes were also calculated. Differential scanning calorimetry (DSC) was used for thermal analysis of the sample. Nanocrystals were induced in the glass by heat-treatment. Strong room temperature upconversion emissions were observed at 415, 540, 554 and 667 nm from Er3+ doped sample under 972 nm Ti-sapphire laser excitation. X-ray diffraction (XRD) measurements revealed the presence of NaErF4 crystallites 35 nm in the glassy matrix. The concentration of nanocrystals is found to be low in the middle of the sample and higher close to the surface. Time correlated single photon counting (TCSPC) was used to measure Er3+ lifetimes.