Strong-field coherent control of isolated attosecond pulse generation

Attosecond science promises to reveal the most fundamental electronic dynamics occurring in matter and it can develop further by meeting two linked technological goals related to high-order harmonic sources: improved spectral tunability (allowing selectivity in addressing electronic transitions) and higher photon flux (permitting to measure low cross-section processes). New developments come through parametric waveform synthesis, which provides control over the shape of field transients, enabling the creation of highly-tunable isolated attosecond pulses via high-harmonic generation. Here we demonstrate that the first goal is fulfilled since central energy, spectral bandwidth/shape and temporal duration of isolated attosecond pulses can be controlled by shaping the laser waveform via two key parameters: the relative-phase between two halves of the multi-octave spanning spectrum, and the overall carrier-envelope phase. These results not only promise to expand the experimental possibilities in attosecond science, but also demonstrate coherent strong-field control of free-electron trajectories using tailored optical waveforms. Attosecond pulse generation needs improvements both in terms of tunability and photon flux for next level attosecond experiments. Here the authors show how to control the HHG emission and its spectral-temporal characteristics by driving the IAP generation with synthesized sub-cycle optical pulses.

Automated summary

Attosecond science can reveal fundamental electronic dynamics in matter by improving spectral tunability and increasing photon flux in high-order harmonic sources. Parametric waveform synthesis enables the generation of highly-tunable isolated attosecond pulses, with central energy, spectral bandwidth/shape, and temporal duration controlled by shaping laser waveforms through relative-phase and carrier-envelope phase parameters. This advancement not only expands experimental possibilities in attosecond science, but also demonstrates coherent strong-field control of free-electron trajectories using tailored optical waveforms.