Laser-driven plasma sources of intense, ultrafast, and coherent radiation

High-power lasers can deliver extreme light intensities, but avoiding damage in optical components requires large beam sizes, hindering further advances. The use of plasma as a medium for generating and manipulating light avoids the damage thresholds of solid materials and can support extraordinarily bright radiation. We discuss here how parametric plasma amplification and relativistic high-order harmonic generation offer paths to the development of light sources with peak powers beyond the capabilities of solid-state optics.