Reproducible Generation and Measurement of Isolated Sub-fs XUV Pulses with Phase-Controlled Few-Cycle Light

Summary

We report on the use of intense phase-controlled few-cycle(5-fs @ 750 nm)pulses for the reproducible generation of high-order-harmonic-like XUV radiation near 100 eV and for measuring the temporal structure of the generated coherent XUV light in a two-colour ionization experiment. Our experiments reveal that control of the carrier-envelope phase of the few-cycle driver allows precise control of the temporal structure of the XUV emission filtered in the cut-off range. Depending on the phase setting, we can generate a single, isolated sub-femtosecond burst (with a cosine driver waveform) or a couple of bursts of comparable energy (with a sine waveform). Our two-colour photoionization measurement permits determination of the XUV pulse duration, the fractional energy carried by satellite pulses and the value of the carrier-envelope phase of the few-cycle driver laser pulse.