# Selective Delamination upon Femtosecond Laser Ablation of Ceramic Surfaces

## TL;DR

This paper investigates how femtosecond laser processing causes selective delamination in yttria-stabilized zirconia ceramics, revealing a controllable method for laser microslicing of brittle ceramics.

## Contribution

It uncovers the mechanism behind laser-induced delamination in semi-transparent ceramics and demonstrates a new approach for precise laser microslicing.

## Key findings

- Delamination occurs above the ablation threshold.
- Delamination threshold depends on laser spot overlap.
- Material undergoes melting on both surfaces during delamination.

## Abstract

We report on the experimental observation of selective delamination of semi-transparent materials on the example of yttria-stabilized zirconia ceramics upon femtosecond laser processing of its surface with low numerical aperture lens. The delamination of a ceramic layer of dozens of micrometers takes place as a by-side effect of surface processing and is observed above the surface ablation threshold. The onset of delamination (delamination threshold) depends on the degree of overlap of the irradiation spots from consecutive laser pulses upon beam scanning over material surface. Analysis of the delaminated layer indicates that the material undergoes melting on its both surfaces. The mechanism of delamination is identified as a complex interplay between the optical response of laser-generated free-electron plasma and nonlinear effects upon laser beam propagation in semi-transparent ceramics. The discovered effect enables controllable laser microslicing of brittle ceramic materials.