Improvement of laser damage resistance and diffraction efficiency of multilayer dielectric diffraction gratings by HF etchback linewidth tailoring

Hoang T. Nguyen; Cindy C. Larson; Jerald A. Britten

doi:10.1117/12.867921

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3 December 2010 Improvement of laser damage resistance and diffraction efficiency of multilayer dielectric diffraction gratings by HF etchback linewidth tailoring

Hoang T. Nguyen, Cindy C. Larson, Jerald A. Britten

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Proceedings Volume 7842, Laser-Induced Damage in Optical Materials: 2010; 78421H (2010) https://doi.org/10.1117/12.867921
Event: Laser Damage Symposium XLII: Annual Symposium on Optical Materials for High Power Lasers, 2010, Boulder, Colorado, United States

Abstract

Multilayer dielectric (MLD) diffraction gratings for Petawatt-class laser systems possess unique laser damage characteristics. Details of the shape of the grating lines and the concentration of absorbing impurities on the surface of the grating structures both have strong effects on laser damage threshold. It is known that electric field enhancement in the solid material comprising the grating lines varies directly with the linewidth and inversely with the line height for equivalent diffraction efficiency. Here, we present an overview of laser damage characteristics of MLD gratings, and describe a process for post-processing ion-beam etched grating lines using very dilute buffered hydrofluoric acid solutions. This process acts simultaneously to reduce grating linewidth and remove surface contaminants, thereby improving laser damage thresholds through two pathways.

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Hoang T. Nguyen, Cindy C. Larson, and Jerald A. Britten "Improvement of laser damage resistance and diffraction efficiency of multilayer dielectric diffraction gratings by HF etchback linewidth tailoring", Proc. SPIE 7842, Laser-Induced Damage in Optical Materials: 2010, 78421H (3 December 2010); https://doi.org/10.1117/12.867921

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