Depth profiling the thermal reflection coefficient of an opaque solid via an inverse thermal wave scattering theory based on the Method of Images

A new formulation of the inverse problem of depth profiling the thermal pro perties of an opaque solid based on one-dimensional photo-generated thermal waves is presented. The inverse problem as posed is linear in a set of lum ped thermal reflection coefficients which account for the return of energy to the surface by all significant heat conduction channels. an analysis bas ed on the Method of Images relates these coefficients to individual values of the interface thermal reflection coefficients in the material. No weak b ackscattering assumption is invoked to linearize the problem. The method yi elds a unique solution subject to a given condition of regularization. Solu tions recovered by the method are stable at experimentally feasible error l evels.