Open AccessMeasuring the ablation threshold fluence in femtosecond laser micromachining with vortex and Bessel pulses
Author(s) -
Reece N. Oosterbeek,
Simon Ashforth,
Owen Bodley,
M. Cather Simpson
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.034558
Subject(s) - optics , fluence , femtosecond , surface micromachining , materials science , bessel beam , ablation , beam (structure) , gaussian beam , laser , laser ablation , bessel function , laser beam quality , laser beams , physics , fabrication , medicine , alternative medicine , engineering , pathology , aerospace engineering
Femtosecond laser micromachining holds significant promise for advanced manufacturing, however uptake has been limited by the low processing speed. Altering the beam shape from its typical Gaussian profile has been attempted to improve efficiency, however virtually all reliable methods for quantifying the efficiency assume a Gaussian beam shape. Here, we describe an approach for quantifying the ablation threshold fluence - the key parameter for comparing efficiency - suitable for weakly focused non-Gaussian beams. We successfully demonstrate this method for Bessel and vortex beams, finding that the ablation threshold depends not just on the material, but the beam shape as well.