Spatio-temporal isolation of attosecond soft X-ray pulses in the water window

TL;DR

This paper reports the experimental demonstration of isolating single attosecond soft X-ray pulses at the water window's carbon K-edge, enabling time-resolved studies of electronic dynamics in materials.

Contribution

It introduces a scalable spatio-temporal isolation method for generating isolated attosecond pulses in the soft X-ray water window.

Findings

Achieved sub-400 as pulse duration at 284 eV

Bandwidth supports 30 as pulse duration

Validated a robust, reproducible isolation approach

Abstract

We demonstrate experimentally the isolation of single attosecond pulses at the carbon K- shell edge in the soft-X-ray water window. Attosecond pulses at photon energies that cover the principal absorption edges of the building blocks of materials are a prerequisite for time resolved probing of the triggering events leading to electronic dynamics such as exciton formation and annihilation. Herewith, we demonstrate successful isolation of individual attosecond pulses at the carbon K edge (284 eV) with a pulse duration below 400 as and with a bandwidth supporting a 30 as pulse duration. Our approach is based on spatio-temporal isolation of ponderomotively shifted harmonics and validates a straightforward and scalable approach for robust and reproducible attosecond pulse isolation.