title: Surface damage of extreme-ultraviolet gratings exposed to high-energy 20-fs laser pulses.
abstract: The damage fluences of gratings for diffraction of ultraviolet radiation, which are used in high-order harmonic generation experiments, have been measured with respect to the fundamental laser beam radiation. We have tested gold and platinum coatings of 40- and 50-nm thickness, respectively, deposited onto fused-silica substrates, after irradiation of high-energy, spatially filtered, 20-fs laser pulses at 780 nm. The damage appears at a fluence of approximately 0.3 J cm(-2) for gold and at a fluence of approximately 0.4 J cm(-2) for platinum. Scanning electron microscopy of the irradiated regions revealed different damaging mechanisms for the two coatings.
authors.affiliation: Laboratorio di Elettronica Quantistica, Istituto Nazionale Fisica della Materia, Universita di Padova, Padova, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Ceccherini
authors.forename: M G
authors.initials: MG
authors.lastname: Pelizzo
authors.forename: P
authors.initials: P
authors.lastname: Villoresi
authors.forename: S
authors.initials: S
authors.lastname: De Silvestri
authors.forename: M
authors.initials: M
authors.lastname: Nisoli
authors.forename: S
authors.initials: S
authors.lastname: Stagira