Depth profiling of thermal relaxation time and thermal conductivity related to hyperbolic heating propagation

By employing a hybrid Newton-like iterative way and a regularization method, the numerical simulations of the depth profile reconstruction of the thermal relaxation time, which is directly related to the thermal wave propagation velocity, for inhomogeneous solid samples have been performed from surface photo-thermal signals. The results demonstrate that the algorithm is effective and stable even under the condition of noise disturbance. The theory and numerical calculation of synchronous inversion about relaxation time and thermal conductivity also be presented.