Nonlinear photoacoustic response of optically heterogeneous two-layered systems: I. Mathematical model of the problem

Present article is devoted to study of nonlinear photoacoustic response of optically heterogeneous two-layered systems. Therefore, based on the system of non-linear equations of heat conduction for gas layer of substrate and optically inhomogeneous two-layer sample, a mathematical model has been developed that describes the features of formation of stationary temperature field and also a nonlinear photoacoustic signal at fundamental and second harmonics generated by these samples. (author)