In situ characterization of laser-induced strong field ionization phenomena

TL;DR

This paper introduces a novel in situ method combining focal imaging and ion measurements to accurately characterize the spatial intensity and duration of strong femtosecond laser pulses, enhancing attosecond science precision.

Contribution

The study presents a new in situ measurement scheme that accurately characterizes laser pulse parameters within the interaction region, addressing a key challenge in attosecond experiments.

Findings

Accurate spatial characterization of laser pulses achieved across various gas densities.

Double ionization and barrier suppression ionization are significant in the measurement.

Method improves the reliability of strong-field and high harmonic generation experiments.

Abstract

Accurately characterizing the intensity and duration of strong-field femtosecond pulses within the interaction volume is crucial for attosecond science. However, this remains a major bottleneck, limiting accuracy of the strong-field, and in particular, high harmonic generation experiments. We present a novel scheme for the in situ measurement and control of spatially resolved strong-field femtosecond pulse intensity and duration within the interaction focal region. Our approach combines conjugate focal imaging with in situ ion measurements using gas densities pertinent to attosecond science experiments. Independent measurements in helium and argon, accompanied by a fitting to a strong field ionization dynamic model, yield accurate and consistent results across a wide range of gas densities and underscores the significance of double ionization, as well as barrier suppression ionization. Direct spatially resolved characterization of the driving laser is a critical step towards resolving the averaging problem in the interaction volume, paving the way for more accurate and reliable attosecond experiments.