Femtosecond LIPSS on indium-tin-oxide thin films at IR wavelengths

TL;DR

This study demonstrates the formation of femtosecond laser-induced periodic surface structures (LIPSS) on indium-tin-oxide thin films at IR wavelengths, revealing a periodicity near one-tenth of the laser wavelength and explaining the formation mechanism through simulations.

Contribution

It provides new insights into LIPSS formation on ITO films at IR wavelengths, combining experimental observations with finite-difference time-domain simulations.

Findings

LIPSS with periodicity close to λ/10 observed on ITO films

Surface field localization leads to periodic absorption enhancement

Finite-difference time-domain simulations support the formation mechanism

Abstract

We investigated laser-induced periodic surface structures (LIPSS) generated on indium-tin-oxide (ITO) thin films with femtosecond laser pulses in the infrared region. Using pulses between 1.6 and 2.4 ${\mu}$m central wavelength, we observed robust LIPSS morphologies with a periodicity close to ${\lambda}$/10. Supporting finite-difference time-domain calculations suggest that the surface forms are rooted in the field localization in the surface pits leading to a periodically increased absorption of the laser pulse energy that creates the observed periodic structures.