Estimating spot size and relating hole diameters with fluence and number of shots for nanosecond and femtosecond laser ablation of polyethylene terephthalate

The relationship between focused spot size, pulse energy, and ablated hole diameter was explored using 266  nm nanosecond pulses and 775  nm femtosecond pulses on polyethylene terephthalate. The spot size of a Gaussian laser beam can be deduced from the diameters of holes machined with single shots...

Full description

Saved in:
Bibliographic Details
Published in:Journal of laser applications 2007-08, Vol.19 (3), p.158-164
Main Authors: Mullan, Claire, O’Connor, Gerard M., Favre, Sebastian, Ilie, Diana, Glynn, Thomas J.
Format: Article
Language:English
Subjects:
femtosecond
hole diameter
laser ablation
nanosecond
spot size
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The relationship between focused spot size, pulse energy, and ablated hole diameter was explored using 266  nm nanosecond pulses and 775  nm femtosecond pulses on polyethylene terephthalate. The spot size of a Gaussian laser beam can be deduced from the diameters of holes machined with single shots at different pulse energies but the results can be influenced by such issues as the thickness of the material and the range of fluence chosen. These limitations of the method were investigated. Multiple shot craters were also measured but gave an overestimation of spot size, particularly in the femtosecond case. A model was developed to predict the diameter for a given energy and number of shots. Tests of the model gave results that agreed well with the predicted values. It was found that for the same total energy smaller holes can be obtained by decreasing the pulse energy and increasing the number of shots. An effective spot size for multiple shots was determined.
ISSN:1042-346X
1938-1387
DOI:10.2351/1.2567797