Determinação das propriedades ópticas e térmicas de vidros teluretos e da cerâmica ferroelétrica PLZT em função da temperatura e do campo elétrico externo

Abstract

The aim of this work was to apply the Thermal Lens Spectrometry, the Optical Interferometry and the Thermal Relaxation Calorimetry to determine the absolute values of the thermo-optical properties of both the TiO2 doped telluride glasses and the transparent ceramic PLZT. The experiments in the glass samples were performed as a function of temperature focusing the regions close to the glass transition temperatures. The studied glasses were: 80% TeO2-20% Li2O (TeLi-00), 80% TeO2-15% Li2O-5% TiO2 (TeLiTi-05) e 80% TeO2-10% Li2O-10% TiO2 (TeLiTi-10). In the case of the PLZT sample the measurements were performed as a function of temperature and also at room temperature as a function of the external electrical field. The studied sample was: Pb0,90La0,10(Zr0,65Ti0,35) 0,98O3]. The results allowed us to perform an evaluation of the nature of the transitions occurred in the samples by monitoring the variation of parameters that are essentials to define the figure of merit of these materials in terms of their application in optical systems, especially for laser developments. As far as we know, this is the first time that thermal lens spectrometry is applied to determine the absolute values of the thermo-optical properties as a function of the electrical field. Our results suggest that the employed procedure of combining the three techniques for measurements as a function of temperature and electrical field could be extended to study other photonic materials.