We have developed low-dispersion (1480 l/mm), resonance-free, diffraction gratings made of dielectric materials resistant to femtosecond laser damage $(SiO_{ 2}/HfO_{ 2})$. A 14 cm diameter sample was fabricated resulting in a mean diffraction efficiency of 99.1% at { \lambda} = 810 nm with 0.4% uniformity using equipment which can fabricate gratings up to 1m diagonal. The implementation of these gratings in the compression of 30 fs pulses in an out-of-plane geometry can result in compressor efficiencies of ~95%. The measured laser absorption is 500x lower than current ultrafast petawatt-class compressor gratings which will enable a substantial increase in average power handling capabilities of these laser systems.
Categories: physics.ins-det physics.optics