QUANTITATIVE THERMAL-WAVE IMAGING - THE ESTIMATION OF DEPTH, SIZE ANDMAGNITUDE OF MATERIAL INHOMOGENEITIES

A technique by which subsurface thermal inhomogeneities can be quantit atively reconstructed from photothermal images is discussed. The appro ach is based on the fact that the photothermal signal can be expressed as the spatial convolution of the Photothermal Point Spread Function and the shape function of the hidden object. Numerical simulations dem onstrate the performance and the limits of the approach. Experimental results obtained from a low thermal contrast sample are presented and compared with the theory.