SINOPSIS

We carried out 3D numerical modeling to understand ultrafast radiative transfer characteristics in multilayer inhomogeneous media, irradiated by a collimated short square pulse train, using the discrete-ordinates method (DOM) in combination with Duhamel's superposition theorem. The DOM was used to first obtain the temporal solution subjected to a single unit step pulse. Duhamel's superposition theorem was then used to reconstruct the response to different kinds of pulse trains. The efficiency of superposition was shown via CPU time comparison with and without use of superposition. The reflectance and transmittance signals are characterized, focusing on the effects of optical thickness, scattering albedo, pulse width and interval, and detection position.