Ripple formation on silver after irradiation with radially polarized ultrashort-pulsed lasers

TL;DR

This study investigates how radially polarized ultrashort laser pulses induce ripple structures on silver surfaces, combining theoretical models and experimental insights to control laser micro-processing outcomes.

Contribution

It introduces a combined hydrodynamical and thermoelastic model to explain ripple formation and demonstrates polarization-based control of surface morphology.

Findings

Surface plasmon excitation influences ripple formation.

Temperature effects induce lattice movements affecting morphology.

Polarization modulation controls ripple size.

Abstract

We report on the morphological effects induced by the inhomogeneous absorption of cylindrically polarized femtosecond laser irradiation of silver (Ag) in sub-ablation conditions. A theoretical prediction of the role of surface plasmon excitation in the production of self-formed periodic ripples structures is evaluated. Furthermore, a combined hydrodynamical and thermoelastic model is presented to account for the influence of temperature-related lattice movements in laser beam conditions that are sufficient to produce material melting. The ability to control the size of the morphological changes via modulating the beam polarization aims to provide a systematic methodology for controlling and optimizing the outcome of laser micro-processing.