The effects of degraded spatial coherence on ultrafast-laser channel etching

When laser-etching channels through solid targets, the etch-rate is known to decrease with increasing depth, partly because of absorption at the sides of the channel. For ultrafast-laser pulses at repetition rates >100 MHz, we show that the etch-rate is also affected by optical properties of the...

Full description

Saved in:
Bibliographic Details
Published in:Optics express 2008-09, Vol.16 (18), p.13606-13616
Main Authors: Dean, Jesse, Bercx, Martin, Frank, Felix, Evans, Rodger, Camacho-López, Santiago, Nantel, Marc, Marjoribanks, Robin
Format: Article
Language:English
Subjects:
Computer Simulation
Computer-Aided Design
Equipment Design
Equipment Failure Analysis
Lasers
Manufactured Materials
Models, Theoretical
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:When laser-etching channels through solid targets, the etch-rate is known to decrease with increasing depth, partly because of absorption at the sides of the channel. For ultrafast-laser pulses at repetition rates >100 MHz, we show that the etch-rate is also affected by optical properties of the beam: the channel acts as a waveguide, and so the pulses will decompose into dispersive normal modes. Additionally, plasma on the inner surface of the channel will cause scattering of the beam. These effects will cause a loss of spatial coherence in the pulse, which will affect the propagated intensity distribution and ultimately the etch-rate. We have characterized this effect for various foil thicknesses to determine the evolution of the beam while drilling through metal.
ISSN:1094-4087
1094-4087
DOI:10.1364/OE.16.013606