The femto-second technology gains of increasing importance in industrial applications. In this context, a new generation of compact and low cost laser sources has to be provided on a commercial basis. Typical pulse durations of these sources are specified in the range from a few hundred femtoup to some pico-seconds, and typical wavelengths are centered around 1030-1080nm. As a consequence, also the demands imposed on high power optical components for these laser sources are rapidly increasing, especially in respect to their power handling capability in the ultra-short pulse range. The present contribution is dedicated to some aspects for improving this quality parameter of optical coatings. The study is based on a set of hafnia and silica mixtures with different compositions and optical band gaps. This material combination displays under ultra-short pulse laser irradiation effects, which are typically for thermal processes. For instance, melting had been observed in the morphology of damaged sides. In this context, models for a prediction of the laser damage thresholds and scaling laws are scrutinized, and have been modified calculating the energy of the electron ensemble. Furthermore, a simple first order approach for the calculation of the temperature was included.

Date Published: 23 November 2011
PDF: 14 pages
Proc. SPIE 8190, Laser-Induced Damage in Optical Materials: 2011, 819004 (23 November 2011); doi: 10.1117/12.899566

Published in SPIE Proceedings Vol. 8190:
Laser-Induced Damage in Optical Materials: 2011
Gregory J. Exarhos; Vitaly E. Gruzdev; Joseph A. Menapace; Detlev Ristau; M. J. Soileau, Editor(s)