Thermal signatures of a localized inhomogeneity in a 2-D participating medium subjected to an ultra-fast step-pulse laser wave

The transport of a train of short-pulse radiation through a 2-D rectangular participating medium consisting of local inhomogeneities is investigated in this article. A collimated beam of step temporal profile is considered. The pulse wave consists of 1 and 4 pulses. The absorbing and scattering participating medium contains a square-shaped local inhomogeneity. The inhomogeneity differs from the rest of the medium by its scattering albedo. The pulse width and the period of the laser wave are of the order of a nano-second. Transmittance and reflectance signals are analyzed for the effects of the extinction coefficient and the scattering albedo. Heat flux distributions inside the medium are also studied. The finite-volume method is used to solve the problem.