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 ~0.3 J cm−2 for gold and at a fluence of ~0.4 J cm−2 for platinum. Scanning electron microscopy of the irradiated regions revealed different damaging mechanisms for the two coatings.
© 1999 Optical Society of America
[Optical Society of America ]
Paolo Ceccherini, Maria-G. Pelizzo, Paolo Villoresi, Sandro De Silvestri, Mauro Nisoli, and Salvatore Stagira, "Surface Damage of Extreme-Ultraviolet Gratings Exposed to High-Energy 20-fs Laser Pulses," Appl. Opt. 38, 4720-4724 (1999)