Raluca A. Negres

The impact of working gas and hafnia-silica composite coatings deposited by ion beam sputtering for 1064nm (Conference Presentation)

Colin M. Harthcock, Amira Guediche, Saaxewer Diop, Jungmin Ha et autres

Multilayer dielectric (MLD) optics for high-fluence lasers are often limited by damage that initiates in the high-index HfO2 layers. Building on the identification of two dominant precursors—nanometer-scale gas bubbles seeded during ion-assisted growth and local non-stoichiometry—we process-optimized ion-beam sputtering (IBS) by replacing …

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Nanosecond dual-wavelength irradiation effects on laser-induced damage in hafnia coatings

Saaxewer B. Diop, Charles Bouyer, Amira Guediche, Guilhem Rouzaud et autres

Nanosecond dual-wavelength laser-induced damage was investigated at 1064 nm ( 1 ω ) and 355 nm ( 3 ω ) on ion-beam-sputtered hafnia single-layer coatings. Single-wavelength 1-on-1 tests were first conducted to establish reference onset fluences. Dual-wavelength tests combined a primary beam …

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Influence of Oxygen Flow and Stoichiometry on Optical Properties and Damage Resistance of Hafnium Oxide Thin Films

Amira Guediche, Saaxewer B. Diop, Raluca A. Negres, L. B. Bayu Aji et autres

Hafnium oxide (HfO2) is predominantly used as a high-index material in multi-layer dielectric coatings for high-peak- and high-average-power lasers, but laser damage often initiates within the HfO2 layers despite their wide bandgap. Oxygen deficiency during deposition can introduce vacancy-related sub-bandgap states and …

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Key parameters influencing laser damage in high-performance optical components

Raluca A. Negres, C. W. Carr

Special Section Guest Editorial: Laser Damage VIII

Jonathan W. Arenberg, Raluca A. Negres, Eyal Feigenbaum, Vitali E. Gruzdev

This Special Section on Laser Damage, Laser Damage VIII, is the eighth in the series of special sections of Optical Engineering focused on the diverse aspects of laser-induced damage (LID) of optical materials, surfaces, and components.Previous special sections on laser damage can …

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Laser damage of crazed electron-beam high-reflectors following infrared and ultraviolet irradiation in the nanosecond pulse regime

Colin M. Harthcock, Amira Guediche, Saaxewer B. Diop, Christopher J. Stolz et autres

Laser damage of optical components can be a limiting factor in scaling the energetics of high-peak and average power laser systems. Specifically for optical coatings, damage under nanosecond pulsed irradiation is initiated by pre-existing defects in the coating layers, including those that …

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Parameters Affecting Laser‐Induced Damage Initiation and Growth

Raluca A. Negres, Christopher Wren Carr

Laser-induced damage in transparent optical materials, or laser damage, generally refers to permanent laser-induced modifications imparted to a material upon laser exposures. This chapter discusses both bulk and surface damage. It describes laser-induced damage behavior, including its stages and several key dependencies …

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Special Section Guest Editorial: Laser Damage VII

Jonathan W. Arenberg, Eyal Feigenbaum, Raluca A. Negres

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Modification of polysilsesquioxane curing for use in anti-reflective coatings

Alan Ramirez, Justin A. Kerszulis, Marcus V. Monticelli, Raluca A. Negres et autres

In this work we showcase the formulation of an anti-reflective (AR), UV/ozone-curable polysilsesquioxane or glass resin (GR) system with a high laser damage threshold suitable for Third-Harmonic Generator (THG) optics. Potassium Dideuterium Phosphate (DKDP) single crystals are used for these non-linear optics …

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Femtosecond 1030-nm mirror thin film damage competition

Colin M. Harthcock, Raluca A. Negres, Gintarė Batavičiūtė, Andrius Melninkaitis

This year’s laser damage competition involves short pulse laser damage on high reflectors tuned for near normal incidence and >99.5% reflectance for 1030 nm. All laser damage testing was done by Lidaris Ltd. via a near Gaussian laser beam from a commercial …

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Broadband 920-nm mirror thin film damage competition

Raluca A. Negres, Kyle R. P. Kafka, Chris J. Smith, Marek Stehlík et autres

The 2023 Laser Damage conference thin-film damage competition was devoted to a survey on the state-of-the-art broadband near-IR multilayer dielectric (MLD) mirrors designed for ultra-short pulsed laser applications. The requirements for the coatings were a minimum reflection of 99.5% at 45-deg incidence …

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Delivering laser performance conditions to enable fusion ignition, and beyond at the National Ignition Facility

JM. Di Nicola, Tayyab I. Suratwala, Lawrence J. Pelz, John E. Heebner et autres

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