You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither SPIE nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the SPIE website.
16 May 2017Laser-induced periodic surface structures formation: investigation of the effect of nonlinear absorption of laser energy in different materials
To get insight into laser-induced periodic surface structures (LIPSS) formation, the relaxation of a modulation in the temperature profile is investigated numerically on surfaces of two different kinds of materials (metals and dielectrics; gold and fused silica as examples) upon irradiation by ultrashort laser pulses. The temperature modulation is assumed to originate from the interference between the incoming laser pulse and the surface electromagnetic wave, which is considered as the main mechanism of LIPSS formation. For comparative studies of laser energy dissipation, a simplified 2D approach is used. It is based on the two-temperature model (TTM) and considers the mechanisms of nonlinear absorption of laser light (multiphoton ionization in fused silica; temperature-dependent thermophysical and optical properties in gold) and relaxation (electron trapping to excitonic states in fused silica). The TTM is coupled with the Drude model, considering the evolution of optical properties as a function of free-carrier density and/or temperature. The development and decay of the lattice temperature modulation, which can govern the LIPSS formation, is followed during electron-lattice thermalization time and beyond. It is shown that strong temperature gradients can form along the surfaces of both kinds of materials under study within the fluence range typical for LIPSS formation. Considerable changes in optical properties of these materials are found as a function of time, including metals, for which a constant reflectivity is usually assumed. Effects of nonlinear absorption on the surface temperature dynamics are reported.
Yoann Levy,Nadezhda M. Bulgakova, andTomáš Mocek
"Laser-induced periodic surface structures formation: investigation of the effect of nonlinear absorption of laser energy in different materials", Proc. SPIE 10228, Nonlinear Optics and Applications X, 102280T (16 May 2017); https://doi.org/10.1117/12.2265698
The alert did not successfully save. Please try again later.
Yoann Levy, Nadezhda M. Bulgakova, Tomáš Mocek, "Laser-induced periodic surface structures formation: investigation of the effect of nonlinear absorption of laser energy in different materials," Proc. SPIE 10228, Nonlinear Optics and Applications X, 102280T (16 May 2017); https://doi.org/10.1117/12.2265698