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Université Jean Monnet – Saint-Etienne |  |
Journal articles
Spontaneous periodic ordering on the surface and in the bulk of dielectrics irradiated by ultrafast laser: a shared electromagnetic origin
Abstract : Periodic self-organization of matter beyond the diffraction limit is a puzzling phenomenon, typical
both for surface and bulk ultrashort laser processing. Here we compare the mechanisms of periodic
nanostructure formation on the surface and in the bulk of fused silica. We show that volume
nanogratings and surface nanoripples having subwavelength periodicity and oriented perpendicular
to the laser polarization share the same electromagnetic origin. The nanostructure orientation is
defined by the near-field local enhancement in the vicinity of the inhomogeneous scattering centers.
The periodicity is attributed to the coherent superposition of the waves scattered at inhomogeneities.
Numerical calculations also support the multipulse accumulation nature of nanogratings formation
on the surface and inside fused silica. Laser surface processing by multiple laser pulses promotes the
transition from the high spatial frequency perpendicularly oriented nanoripples to the low spatial
frequency ripples, parallel or perpendicular to the laser polarization. The latter structures also share the
electromagnetic origin, but are related to the incident field interference with the scattered far-field of
rough non-metallic or transiently metallic surfaces. The characteristic ripple appearances are predicted
by combined electromagnetic and thermo-mechanical approaches and supported by SEM images of the
final surface morphology and by time-resolved pump-probe diffraction measurements.
Cited literature [74 references]
https://hal-ujm.archives-ouvertes.fr/ujm-01616533
Contributor : Tatiana Itina <>
Submitted on : Friday, October 13, 2017 - 5:54:30 PM
Last modification on : Wednesday, October 14, 2020 - 4:22:03 AM
Long-term archiving on: : Sunday, January 14, 2018 - 2:07:47 PM
Contributor : Tatiana Itina <>
Submitted on : Friday, October 13, 2017 - 5:54:30 PM
Last modification on : Wednesday, October 14, 2020 - 4:22:03 AM
Long-term archiving on: : Sunday, January 14, 2018 - 2:07:47 PM
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