Application of the thermal quadrupole method to the propagation of thermal waves in multilayered cylinders

Up to now, research in photothermal techniques has been mainly restricted to samples with flat surfaces. In this work the surface temperature oscillation of multilayered cylindrical samples which are heated by a modulated light beam is calculated by using the quadrupole method. Different illumination geometries have been studied. Moreover, the lack of adherence between layers, as well as heat losses at the surface, has been considered in the model. Following this theoretical approach, photothermal techniques can be used for the quantitative thermophysical characterization of cylindrical samples with continuously varying in-depth thermal conductivity. (c) 2006 American Institute of Physics.