  Femtosecond pulsed lasers have been widely used over the past decades for
precise materials structuring at the micro- and nano- scales. In order, though,
to realize efficient material processing and account for the formation of laser
induced periodic surfaces structures (LIPSS), it is very important to
understand the fundamental laser-matter interaction processes. A significant
contribution to the LIPSS profile appears to originate from the electromagnetic
fingerprint of the laser source. In this work, we follow a systematic approach
to predict the pulse-by-pulse formation of LIPSS on metals due to the
development of a spatially periodic energy deposition that results from the
interference of electromagnetic far fields on a non-flat surface profile. On
the other hand, we demonstrate that the induced electromagnetic effects, alone,
are not sufficient to allow the LIPSS formation, therefore, we emphasize on the
crucial role of electron diffusion and electron-phonon coupling on the
formation of stable periodic structures. Gold and stainless Steel are
considered as two materials to test the theoretical model while simulation
results appear to confirm the experimental results that, unlike gold,
fabrication of pronounced LIPSS on stainless Steel is feasible.
