Generation and characterisation of isolated attosecond pulses at 100kHz repetition rate

TL;DR

This paper reports the generation and full characterization of isolated attosecond pulses at a 100 kHz repetition rate, enabling advanced attosecond spectroscopy with high photon flux.

Contribution

It demonstrates the production of high-flux, isolated attosecond pulses at 100 kHz, surpassing previous repetition rates and enabling new experimental capabilities.

Findings

Achieved 10^6 XUV photons per pulse at 100 kHz

Confirmed pulses are dominated by a single attosecond pulse

Enabled attosecond streaking experiments at high repetition rate

Abstract

The generation of coherent light pulses in the extreme ultraviolet (XUV) spectral region with attosecond pulse durations constitutes the foundation of the field of attosecond science. Twenty years after the first demonstration of isolated attosecond pulses, they continue to be a unique tool enabling the observation and control of electron dynamics in atoms, molecules and solids. It has long been identified that an increase in the repetition rate of attosecond light sources is necessary for many applications in atomic and molecular physics, surface science, and imaging. Although high harmonic generation (HHG) at repetition rates exceeding 100 kHz, showing a continuum in the cut-off region of the XUV spectrum was already demonstrated in 2013, the number of photons per pulse was insufficient to perform pulse characterisation via attosecond streaking, let alone to perform a pump-probe experiment. Here we report on the generation and full characterisation of XUV attosecond pulses via HHG driven by near-single-cycle pulses at a repetition rate of 100 kHz. The high number of 10^6 XUV photons per pulse on target enables attosecond electron streaking experiments through which the XUV pulses are determined to consist of a dominant single attosecond pulse. These results open the door for attosecond pump-probe spectroscopy studies at a repetition rate one or two orders of magnitude above current implementations.