Anti-Reflection Coatings Using Laser-Induced Damage Threshold & Photothermal Common-Path Interferometry

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Comparison of Single-Layer and Double-Layer Anti-Reflection Coatings Using Laser-Induced Damage Threshold and Photothermal Common-Path Interferometry

Caspar Clark
Helia Photonics Ltd., Livingston EH54 7EJ, UK

Riccardo Bassiri, Ashot Markosyan, Martin M. Fejer
E. L. Ginzton Laboratory, Stanford University, Stanford, CA 94305, USA

Iain W. Martin, Peter G. Murray, Sheila Rowan
Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK

Des Gibson
Scottish Universities Physics Alliance, Institute of Thin Films, Sensors & Imaging, School of Engineering and Computing, University of the West of Scotland, Paisley PA1 2BE, UK

http://www.mdpi.com/2079-6412/6/2/20/htm

abstract
The dielectric thin-film coating on high-power optical components is often the weakest region and will fail at elevated optical fluences. A comparison of single-layer coatings of ZrO2, LiF, Ta2O5, SiN, and SiO2 along with anti-reflection (AR) coatings optimized at 1064 nm comprised of ZrO2 and Ta2O5 was made, and the results of photothermal common-path interferometry (PCI) and a laser-induced damage threshold (LIDT) are presented here. The coatings were grown by radio frequency (RF) sputtering, pulsed direct-current (DC) sputtering, ion-assisted electron beam evaporation (IAD), and thermal evaporation. Test regimes for LIDT used pulse durations of 9.6 ns at 100 Hz for 1000-on-1 and 1-on-1 regimes at 1064 nm for single-layer and AR coatings, and 20 ns at 20 Hz for a 200-on-1 regime to compare the //ZrO2/SiO2 AR coating.

Keywords: laser-induced damage; photothermal common-path interferometry; optical coatings; 1064nm