Thermo-optical spectroscopic investigation of new Nd3+-doped fluoro-aluminophosphate glasses

Abstract Fluorophosphate glasses in the compositional system 25BaF 2 -25SrF 2 -10Al(PO 3 ) 3 -20AlF 3 -(20-z)YF 3 :zNdF 3 with z = 0.5, 1, 2, 4 and 8 mol % were prepared and characterized from the spectroscopic point of view, as potential laser active media. The thermal optical properties of the glasses were evaluated using the Thermal Lens Technique and from the analysis of the heat generated upon excitation (and the consequent change in refractive index), the fluorescence quantum efficiencies η were determined for samples doped with different Nd 3+ concentrations. These values were then compared to those obtained by employing the radiative lifetime values determined from the Judd Ofelt theory and a very good agreement was verified between the experimental and theoretical results. A nearly zero change in optical pathlength ds/dT = 2.5 × 10 −6  K −1 and thermal conductivity values ranging from (12–7) × 10 −3  W/Kcm, favorable for laser action, were determined for samples doped with 0.5–8 mol %.