Constructive feedback for the growth of laser‐induced periodic surface structures

Abstract

We study the formation and growth of laser‐induced periodic surface structures (LIPSSs) with the finite‐difference time‐domain (FDTD) method. We use a recently proposed inter‐pulse feedback method to account for the evolution of the surface morphology between each laser pulse sent to the surface of the processed material. This method has been used with an ablation‐like mechanism, by removing material exposed to a light intensity higher than a given threshold. We propose an inverse mechanism, an expansion‐like mechanism, able to grow structures that the ablation‐like process cannot. This allows us to introduce the notions of constructive and destructive feedback and explains a strong contradiction between the standard Sipe‐Drude theory and the experimental observations, i.e. the formation on metals of structures usually linked to wide band gap dielectrics. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Spontaneous periodic ordering on the surface and in the bulk of dielectrics irradiated by ultrafast laser: a shared electromagnetic origin

“…Another important conclusion is that the discussed electromagnetic multipulse feedback results in the periodic formation of nanogratings, oriented always perpendicular to laser polarization. This way, volume nanogratings with parallel orientation to laser polarization and reported in few semiconductors 43 , 64 , should have different formation mechanism, either related to different electromagnetic interaction, for instance, coherent superposition of the scattered far-fields from single intrinsic nanovoids, or different multipulse feedback 65 .…”

Maxwell Meets Marangoni—A Review of Theories on Laser‐Induced Periodic Surface Structures

“…[73] This allowed to construct a carrier density and ablation depth-dependent "morphological map" of a plethora of HSFL, LSFL, and admixtures of both being parallel or perpendicular to the laser beam polarization. Déziel et al [77] extended that FDTD-feedback simulations to account for expansion-like mechanisms in the LIPSS formation process as they may be involved in sub-ablative conditions via hydrodynamic melt-flows. This allowed to explore the growth of a larger class of nanostructure surface morphologies, including LIPSS on dielectrics and metals.…”

“…Déziel et al. [ 77 ] extended that FDTD‐feedback simulations to account for expansion‐like mechanisms in the LIPSS formation process as they may be involved in sub‐ablative conditions via hydrodynamic melt‐flows. This allowed to explore the growth of a larger class of nanostructure surface morphologies, including LIPSS on dielectrics and metals.…”

High-frequency periodic patterns driven by non-radiative fields coupled with Marangoni convection instabilities on laser-excited metal surfaces

“…The electromagnetic approaches considering light interaction with surface inhomogeneities predict polarization-dependent distribution of non-radiative scattered fields on rough surfaces with strong dispersion of high spatial frequencies [41,43,62]. This results in quasi-periodic patterns via pulse-by-pulse feedback mechanisms, such as ablation processes, surface tension or recoil pressure-driven melt flows [37,41,54,63]. Here, the roughness is not limited to pristine irregular topography but can be induced by laser, for example, as in the regimes of spallation and sub-surface cavitation [18,[20][21][22], Rayleigh-Taylor instability in thin melt layer [20], or material redeposition on the surface [64].…”