Thermal stability and luminescence features of phosphate glasses containing K2TeO3 as promising laser materials

Abstract

In this paper an attempt was made to investigate the compositional, microstructural, thermal and optical properties of 40P2O5- 30ZnO- 20BaF2- 3.8K2TeO3- 1.2Al2O3- 5Nb2O5- 30,000 ppm Er2O3 (PZBKTANEr) novel glasses fabricated by the melt quench technique. The amorphous nature of the glasses was confirmed by X-ray diffraction studies. We estimated the glass transition temperature and thermal stability against the crystallization of present glasses by using differential thermal analysis (DTA). The results of the differential thermal analysis (DTA) indicate that (PZBKTANEr) glasses have a high thermal stability and low tendency to crystallization.The optical absorption edge has been evaluated within the Urbach approach by using UV–vis-NIR spectroscopy. Moreover, the Judd– Ofelt parameters Ω2, Ω4 and Ω6 the oscillator strength type transition probabilities, spectroscopic quality factors, branching ratios and radiative lifetimes of several excited states of Er3+ have been evaluated. The classical Mc Cumber theory was used to evaluate the emission cross-sections for the 4I15/2 → 4I13/2 transition at a wavelength of around 1.54 μm. Gain cross-section for the Er3+ laser transition 4I15/2 → 4I13/2 was obtained. The effective emission cross section bandwidth FWHM (75.924 nm) and height stimulated emission cross-section (5.5 × 10−21 cm−2) of present glasses were reported. Hence the thermal and spectroscopic properties indicate that this glass doped with Er3+ can be used for application of the optical device. Furthermore the structure of this glass was analyzed by Raman spectroscopy.