Our article “Transient laser-induced periodic surface structures revealed by time-resolved EUV diffuse scattering” has been published in Laser & Photonics Reviews.
Led by first author Dmitriy Ksenzov, together with Christian Gutt and an international team of researchers from Germany, Italy, France, and the United States, the study provides new insight into the earliest stages of laser-induced surface pattern formation.
Using time-resolved extreme ultraviolet (EUV) diffuse scattering at the FERMI free-electron laser in Trieste, the researchers investigated the response of metallic films and multilayers to femtosecond laser irradiation at fluences well below the damage threshold. The experiments revealed transient surface patterns with the characteristic reciprocal-space signatures of laser-induced periodic surface structures (LIPSS).
Remarkably, these structures emerge within only a few picoseconds after laser excitation and disappear again over several hundred picoseconds, leaving no permanent modification of the surface.
The transient patterns originate from interference between the incident laser beam and light scattered by the intrinsic surface roughness. This produces a spatial modulation of the absorbed energy and, consequently, of the temperature. The resulting nonuniform heating induces thermoelastic surface displacements, which decay as the spatial temperature modulation relaxes over several hundred picoseconds.
The results shed light on the mechanisms involved in the early stages of laser-induced surface pattern formation and demonstrate how time-resolved EUV scattering can directly probe ultrafast surface dynamics in reciprocal space.
Publication:
D. Ksenzov et al., “Transient laser-induced periodic surface structures revealed by time-resolved EUV diffuse scattering,” Laser & Photonics Reviews (2026).
Read the article: https://doi.org/10.1002/lpor.71817