Large aperture, high-efficiency multilayer dielectric reflection gratings

We have designed and fabricated a 355 /spl times/ 150 mm multilayer dielectric diffraction grating, 1800 l/mm for 1030 nm light, that exhibits > 99% diffraction efficiency and a diffracted wavefront flatness of < 0.15 /spl lambda/. This grating is an enabling component of a 2 ps, high rep-rate machining laser currently in operation at LLNL.