Electrostriction
force induced by light in isotropic media should be treated as based on Coulomb
and Lorentz forces applied to fast oscillating dipoles.
Lorentz
force of electrostriction pressure for standing light wave is not equal to zero.
Volumes
of maximal electrostriction pressure and maximum electromagnetic field density
are different for a travelling light wave.
Nanopaterning
and “optical tweezers” are the mechanisms of laser etching by respectively
travelling or standing light wave.
Semiconductor Physics, Quantum Electronics & Optoelectronics, 21 (2), P. 160-166 (2018).
DOI: https://doi.org/10.15407/spqeo21.02.160
The role of magnetic component of a strong light field in electrostrictive effect
L.V. Poperenko, V.V. Prorok, S.G. Rozouvan, I.A. Shaykevich
Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska st. 01601, Kyiv, Ukraine E-mail: sgr@univ.kiev.ua
Abstract. Electrostriction forces during laser ablation have been studied both theoretically and experimentally. The components of electroctrostriction force for inhomogeneous electromagnetic field near a substrate were proposed to be taken similarly to those in gases within nonresonant spectral region. Nonzero Lorentz force in standing light wave was found to be responsible for different morphology of the nanostructured surface as compared to etching the transient substrate. Our experiments were performed using the femtosecond laser focused on polished glass and Al-coated glass surfaces. The treated surfaces were studied using atomic force microscopy with the spatial resolution of 30 nm. Nanoscale patterning of the etched surface spots was explained in the frames of theoretical modeling. Possible spatial locations of electrostriction force components in the Gauss profile laser beam have been also discussed.
Keywords: electrostriction pressure, Lorentz force, femtosecond laser pulses, nanoparticles.
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