Photo-acoustic spectroscopy and quantum efficiency of Yb3+ doped alumino silicate glasses

Abstract

In this contribution, we analyze the effect of several preparation methods of Yb3+ doped alumino silicate glasses on their quantum efficiency by using photo-acoustic measurements in comparison to standard measurement methods including the determination via the fluorescence lifetime and an integrating sphere setup. The preparation methods focused on decreasing the OH concentration by means of fluorine-substitution and/or applying dry melting atmospheres, which led to an increase in the measured fluorescence lifetime. However, it was found that the influence of these methods on radiative properties such as the measured fluorescence lifetime alone does not per se give exact information about the actual quantum efficiency of the sample. The determination of the quantum efficiency by means of fluorescence lifetime shows inaccuracies when refractive index changing elements such as fluorine are incorporated into the glass. Since fluorine not only eliminates OH from the glass but also increases the "intrinsic" radiative fluorescence lifetime, which is needed to calculate the quantum efficiency, it is difficult to separate lifetime quenching from purely radiative effects. The approach used in this contribution offers a possibility to disentangle radiative from non-radiative properties which is not possible by using fluorescence lifetime measurements alone and allows an accurate determination of the quantum efficiency of a given sample. The comparative determination by an integrating sphere setup leads to the well-known problem of reabsorption which embodies itself in the measurement of too low quantum efficiencies, especially for samples with small quantum efficiencies

Structure Prediction of Rare Earth Doped BaO and MgO Containing Aluminosilicate Glasses–the Model Case of Gd2O3

“…Recently, several studies on rare earth doped aluminosilicate glasses were published. As dopants, ytterbium, samarium, europium, and other ions were used [ 11 , 12 , 13 , 14 ]. It was shown that the base composition of glass has a strong impact on the luminescence properties of the dopant rare earth ions, e.g., the spectral shape of their absorption and emission spectra as well as their luminescence lifetimes.…”

Investigation of Yb3+-doped alumino-silicate glasses for high energy class diode pumped solid state lasers

“…Since for lower temperatures the probability of multi-phonon processes is reduced, early samples with higher OH-concentrations showed a significant temperature dependence, while the low OH sample remained nearly unaffected. This suggests that these samples reach a pretty good quantum efficiency, which was also confirmed by photo acoustic measurements [13].…”

Polarization Properties and Polarization Depth Profiles of (Cd:Zn)S/P(VDF-TrFE) Composite Films in Dependence of Optical Excitation

“…Consequently in this special case, the PA-measurements can be used to determine whether the particle concentration has an influence on the thermal diffusivity DS of the samples in comparison to the pristine P(VDF-TrFE) 70/30, for which DS=1.09·10−3 cm2/normals [39]. The specific PA measurements were carried out using an experimental setup described in [48] (Figure 2a). This setup was supplemented by a polished brass cylinder (4 mm thickness, 8 mm diameter, Figure 2b), placed inside the photoacoustic cell to decrease the volume of the gas tight chamber resulting in an increased SA.…”