Ripple formation on Nickel irradiated with radially polarized femtosecond beams

TL;DR

This study investigates how radially polarized femtosecond laser beams induce ripple structures on nickel surfaces, combining theoretical modeling and experiments to understand and control surface morphology for laser micro-processing.

Contribution

It introduces a combined hydrodynamical and thermoelastic model to predict ripple formation under radially polarized femtosecond laser irradiation on nickel surfaces.

Findings

Radially polarized beams produce smaller ripple periodicity than linearly polarized beams.

Theoretical predictions align well with experimental results.

Controlling beam polarization can optimize laser micro-processing outcomes.

Abstract

We report on the morphological effects induced by the inhomogeneous absorption of radially polarized femtosecond laser irradiation of nickel (Ni) in sub-ablation conditions. A theoretical prediction of the morphology profile is performed and the role of surface plasmon excitation in the production of self-formed periodic ripples structures is evaluated. Results indicate a smaller periodicity of the ripples profile compared to that attained under linearly polarized irradiation conditions. A combined hydrodynamical and thermoelastic model is presented in laser beam conditions that lead to material melting. The simulation results are presented to be in good agreement with the experimental findings. The ability to control the size of the morphological changes via modulating the beam polarization may provide an additional route for controlling and optimizing the outcome of laser micro-processing