# Optical X-ray 'stopwatch' accurately measures 170-attosecond pulses of ångström wavelength

- Published: 2026-11-05 17:15 UTC
- Section: Science › Instruments & experiments
- Tags: attosecond pulses, X-ray stopwatch, ångström wavelength, pulse duration measurement, electron motion, atoms and molecules, optical metrology
- URL: https://realtech.media/news/rt-908376f355e7aa2f92514448_optical_x_ray/

**Ångström-wavelength X-ray pulses of 170 attoseconds have been measured accurately. The same optical system can time electron motion inside atoms and molecules.**

![Optical X-ray 'stopwatch' accurately measures 170-attosecond pulses of ångström wavelength](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/732ae186a5ab59c8.jpg)
*Idaho National Laboratory, Wikimedia Commons, CC BY 2.0*

Nature reports that the duration of ångström-wavelength X-ray pulses lasting 170 attoseconds has been measured accurately. [1] The measurement was made with an optical system designed for precision pulse duration metrology.

The same system can serve as a "stopwatch" for the rapid motion of electrons inside atoms and molecules. Short pulses generated by the system could be used to observe electrons moving around atomic nuclei. [1]

## Sources

1. [Nature](https://doi.org/10.1038/d41586-026-03423-2)
2. [Nature](https://www.nature.com/articles/d41586-026-03423-2)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-908376f355e7aa2f92514448_optical_x_ray/