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Journal articles
Ultrafast laser nanostructuring in bulk silica, a “slow” microexplosion
Abstract : Ultrafast laser microexplosions in bulk material create extreme conditions at mesoscopic scales and are essential to the
synthesis of extraordinary matter structural phases and to light structuring beyond the diffraction limit. Observing the
transformation cycle can elucidate their evolution. We discuss multiscale relaxation dynamics in the formation of
nanoscale structures in laser-irradiated fused silica. Tightly focused ultrafast nondiffractive Bessel beams are used
to generate microexplosions that lead to uniform voids. These trigger thermodynamic nonequilibrium conditions
in one-dimensional geometries with record excitation confinement down to 100 nm and electronic pressures in
the gigapascal range. Time-resolved phase-contrast microscopy on nanosecond to microsecond scales indicates that
void formation is a slow process developing from low-viscosity phases after persistent plasma fluid stages signaled via
nanosecond-long luminescence. The void evolution is not necessarily driven by rarefaction following initial pressure
relaxation, but involves molecular kinetics and stress mechanisms that interfere with the evolution of the liquid phase
and induce cavitation. Heat transport is also visualized. Higher energy leads to hydrodynamic instabilities and void
fragmentation. The dynamic view helps us understand material transformation under confinement.
https://hal-ujm.archives-ouvertes.fr/ujm-01578041
Contributor : Razvan Stoian <>
Submitted on : Monday, August 28, 2017 - 3:49:15 PM
Last modification on : Monday, December 14, 2020 - 3:39:28 PM
Contributor : Razvan Stoian <>
Submitted on : Monday, August 28, 2017 - 3:49:15 PM
Last modification on : Monday, December 14, 2020 - 3:39:28 PM
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