Harmonics from Solid Targets – Bright attosecond keV radiation

The generation of ultrashort flashes of XUV and X-ray light is currently one of the exciting frontiers of science. Development of such sources will open up physical phenomena to experimental investigation on an unprecedented temporal and spatial scale. Theoretical considerations show that harmonics from solid targets are emitted as a train of attosecond pulses and that individual pulses can indeed be isolated. Recent results will be presented that demonstrate for the first time that keV harmonics can in fact be generated using lasers with intensities in excess of 1020 Wcm-2. The harmonics are shown to be emitted into a narrow specular cone with high conversion efficiency opening up the path to bright pulses of attosecond and possibly even shorter pulses.