Plasma gratings for ultrafast lasers at and beyond the multi-petawatt scale*

The peak power that can be delivered by the largest laser facilities operating today is limited by damage to their optical components: higher powers require either much larger or higher-damage-threshold optics. Although current optical technology can be used to build lasers at the multi-petawatt scale, final optics are expensive and delicate, and there is no clear path to developing lasers at significantly higher powers using existing approaches. Plasma optics provide an approach for reaching extreme powers; since the damage threshold of a plasma optic can be two to six orders of magnitude higher than that of a solid-state optic, compact high-power components are possible. Here we discuss the integration of plasma gratings into high-power laser systems and the design of plasma-based lasers beyond the multi-petawatt scale. This includes theoretical and experimental results on the construction and performance of plasma gratings and other components potentially suitable for replacing gratings and mirrors in ultra-high-power lasers. Existing and under-development multi-petawatt lasers provide platforms for testing plasma optics at scales relevant to future ultra-high-power laser systems, so the scaling of plasma optics to tests at the multi-petawatt scale will be a key step in the development of ultra-high-power plasma-based lasers.