Dataset to accompany publication: Imaging solvated oxygen atoms with a femtosecond laser

This dataset includes the measurements that accompany the manuscript "Imaging solvated oxygen atoms with a femtosecond laser", available at https://doi.org/10.1038/s41467-025-66196-8. Imaging of solvated oxygen atoms was performed using femtosecond two-photon absorption laser-induced fluorescence (TALIF), where the fluorescence signal was collected using an ICCD camera (Princeton Instruments). The ICCD images included in the dataset can be used to reproduce all figures in the text of the manuscript and the density calibration for atomic oxygen, as outlined in the README. Additional details regarding the analysis of the ICCD images or the density calibration can be provided upon request to the corresponding author. The abstract for the accepted manuscript is as follows: As a powerful oxidant, atomic oxygen (O) holds considerable promise for a variety of biomedical and industrial applications. However, the inability to quantify solvated oxygen atoms has prevented the determination of the fundamental parameters governing its behaviour in relevant aqueous environments. Here, we directly image ground-state oxygen atoms in water using femtosecond two-photon absorption laser-induced fluorescence. Measurements show that oxygen atoms persist for tens of microseconds in water, penetrating hundreds of micrometres into the liquid. This observed longevity has significant implications, suggesting a need to re-evaluate existing models of solvated atomic oxygen reactivity and transport. Beyond atomic oxygen, this technique is broadly applicable to other solvated atomic species of interest, including nitrogen (N) and hydrogen (H). This work establishes that radical atomic species can be quantified in liquid with ultrafast laser spectroscopy, providing the basis for the determination of key properties including reaction rates, chemical lifetimes, and Henry’s law constants.