Ultrabroadband monocycle infrared light wave synthesis

Intense, few-cycle near-infrared light appears to be an enabling technology for extending high-order harmonic generation to photon energies of several keV, holding promise of

• creating the first laboratory source of coherent hard X-rays,
• pushing the frontiers of attosecond metrology and
• realising atomic-resolution 4D electron imaging by attosecond X-ray diffraction (C.1.1).

The development of such a source has been pioneered¹⁾ at MPQ and will make a multi-kHz, terawatt-scale, few-cycle infrared (λ_carrier ∼ 2100 nm) source (LWS-1) available for MAP research by the end of 2006²⁾. In order to allow the potential offered by intense infrared light to be fully exploited for creating the next-generation attosecond sources (photon energy ∼ 300 – 3000 eV, pulse duration < 30 as), the bandwidth must be increased beyond an octave (∼ 1000 – 3000 nm) and the waveform be precisely controlled. This is the major goal of this project. To this end, an infrared supercontinuum will be produced by self-phase modulation of the pulses from LWS-1 followed by adjustable group-delay dispersion control in a system similar to that outlined in A.1.2. The resultant few-cycle to sub-cycle infrared waveforms will again be sampled by attosecond pulses³⁾ in the same setup, subsequently being used for attosecond control and probing experiments of electronic and molecular dynamics (C.1, C.2).