Chiral patterning of rough surfaces with vortex laser beams: from structured polarization to twisted forces

TL;DR

This paper demonstrates how vortex laser beams with structured polarization can induce chiral patterns on rough surfaces through twisted optical forces, advancing laser surface engineering techniques.

Contribution

It introduces a theoretical approach using numerical simulations to control surface chirality with vortex laser beams, highlighting the role of polarization and inhomogeneous light fields.

Findings

Vortex beams generate asymmetric torque forces affecting surface dynamics.

Structured light fields create intricate chiral surface patterns.

Polarization and spatial inhomogeneity are crucial for surface patterning.

Abstract

The ability to create surface structures with precisely controlled chirality remains a major challenge in laser-matter interaction experiments. In this work, we theoretically study the interaction of vortex laser beams, characterized by spiral polarization patterns and twisted wavefronts, with rough metallic surfaces in order to create surface patterns with chirality. Using numerical simulations based on the finite-difference time-domain method, we investigate how spin and orbital angular momenta influence the inhomogeneous energy absorption at the surface and generate twisted optical forces that can drive topographic reorganization. We show how different structured light fields can create intricate patterns with chiral features on a material surface. We emphasize the crucial role of polarization and spatial inhomogeneity of the light field in the generation of asymmetric torque forces that directly affect the surface dynamics. Our electromagnetic simulations show how vortex beams can be used to create chiral surface structures, expanding our knowledge of laser-generated periodic surface structures and opening up new possibilities for chiral surface engineering.