Thermo-optical properties and nonradiative quantum efficiency of Er3+-doped and Er3+/Tm3+-co-doped tellurite glasses

Thermal lens (TL) measurements were performed in tellurite glasses, 70Te02-19WO 3 -7Na 2 O-4Nb 2 O 5 (mol%), undoped, doped with Er 3+ (1.19 x 10 20 ions/cm 3 ) and co-doped with Er 3+ (1.19 x 10 20 ions/cm 3 )/Tm 3+ (1.56 x 10 20 ions/cm 3 ). The absolute nonradiative quantum efficiency (φ) was determined by the TL method. The φ values for Er 3+ /Tm 3+ -co-doped and Er 3+ -doped tellurite glasses were 0.98 and 0.74, respectively. Fluorescence spectra were performed at λ e = 488 nm and used to estimate the fluorescence quantum efficiency (η) using the TL results. These values were compared with results obtained by Judd-Ofelt calculations.