2 μm spectroscopic investigation of Tm3+-doped tellurite glass fiber

TmF3 doped TeO2–ZnO–La2O3 (TZL) glasses and fibers have been prepared by the conventional melt-quenching and suction casting methods, respectively. 2 μm emission properties and energy transfer mechanisms of the TZL glasses and fibers have been analyzed and discussed. The oscillator strength, Judd–Ofelt parameters, radiative transition probability and radiative lifetime of Tm3+ have been calculated based on the absorption spectra and Judd–Ofelt theory. The maximum emission cross-section of Tm3+ is 6.9 × 10−21 cm2 near 2 μm. Emission spectra have been obtained from both TZL fibers and bulk glass when excited with a 794 nm pump. The results of 2 μm emission spectra indicate that the line width of Tm3+ measured in fibers is narrower than that in the bulk glass sample. The peak position of the emission spectra shifts to longer wavelength with increment of the fiber length.