Large area ion beam sputtered dielectric ultrafast mirrors for petawatt laser beamlines.

The latest advances in petawatt laser technology within the ELI Beamlines project have stimulated the development of large surface area dielectrically coated mirrors meeting all demanding requirements for guiding the compressed 30 J, 25 fs HAPLS laser beam at 10 Hz repetition rate and a center wavelength of 810 nm entirely in vacuum. We describe the production and evaluation of TaO/HfO/SiO ion beam sputtered coated (440 × 290 × 75) mm beam transport mirrors. No crazing was observed after thirty vacuum-air cycles.