High harmonics from solid surfaces as a source of ultra-bright XUV radiation for experiments

Abstract

The coherent high-order harmonic generation from the interaction of ultra-intense femtosecond laser pulses with solid density plasmas holds promise for tabletop sources of extreme ultraviolet (XUV) and soft x-ray radiation with attosecond duration and unprecedented intensities. Together with the generation of mono-energetic electron beams from gas jets and capillaries and the generation of mono-energetic ions from thin foils, this offers a unique tool box of tabletop-laser-generated radiation sources for a wide range of applications previously only accessible with large-scale accelerator and synchrotron-radiation facilities. Especially, the generation of high harmonics from laser plasmas has the potential of being applied to a wide range of experiments from plasma physics to molecular dynamics. So far the studies addressing the generation of high harmonics from laser-generated overcritical plasma surfaces have concentrated mainly on the characterization of the harmonic beams themselves not considering how, in a next step, these beams could be applied to experiments. In this paper we discuss the generation of surface harmonics with the ATLAS (800 mJ, 40 fs) laser system with the emphasis on the transport, spectral shaping refocusing of the harmonic beams, all of these being absolute prerequisites for multi-shot experiments. We also present considerations for future improvements and possible future experiments exploiting the full potential of high harmonic radiation from solid targets.