Large area multilayer-dielectric (MLD) gratings for high energy pulse compression have been manufactured using a new exposure method called scanning beam interference lithography (SBIL).This technique uses two small beams to form a small area of low distortion, high contrast fringes.The fringes in this small area are phase-locked to a substrate on an x-y stage.As the stage and substrate are scanned underneath the illuminating fringe-spot a resist layer is exposed.The diagram at right shows the fundamental operation of the system.Light from a laser is split into two beams which recombine to form fringes at the substrate (the details of the fringe-locking system are omitted from this diagram).