Abstract
The focussed spot size of industrial laser beams is a critical processing parameter in most laser machining applications as it determines the machined feature size and the irradiance produced by the laser at the material interface. There are a number of standard methods available for accurately measuring and analysing the focussed spot. These methods often require expensive equipment that can be time consuming and difficult to set up in a production environment.This paper presents an investigation into a cost effective and straightforward method for the measurement of focussed laser spot sizes based on drilling of holes in mylar film. It can be shown that the slope of a plot of the square of the hole diameter versus the natural log of the laser-pulse energy is equal to twice the square of the spot radius. A measure of the laser spot size can be calculated by generating laser-drilled holes at number of laser pulse energies. The practicality and accuracy of this method is investigated in this paper for a number of laser types including a diode pumped solid state laser (UV DPSS) operating at the third harmonic (355nm), a femtosecond laser and a flash lamp pumped Nd:YAG laser. A comparison between the measured results and the results generated with other available techniques is also presented.
| Original language | English (Ireland) |
|---|---|
| Title of host publication | Investigation of a method for the determination of the focussed spot size of industrial laser beams based on the drilling of holes in Mylar film |
| Number of pages | 12 |
| Volume | 4876 |
| Publication status | Published - 1 Mar 2003 |
Authors (Note for portal: view the doc link for the full list of authors)
- Authors
- Howard, H,Conneely, A,O'Connor, G,Glynn, T,Blau, WJ,Donegan, JF,Duke, AF,MacCraith, JA,McMillan, ND,OConnor, GM,OMongain, E,Toal, V,McLaughlin, JA