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Updated: May 10, 2026
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An Experimental Protocol for Femtosecond NIR/UV - XUV Pump-Probe Experiments with Free-Electron Lasers
Published on: October 23, 2018
In situ focus characterization by ablation technique to enable optics alignment at an XUV FEL source
N Gerasimova1, S Dziarzhytski, H Weigelt
1Deutsches Electronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany. natalia.gerasimova@xfel.eu
The Review of Scientific Instruments
|July 5, 2013
Summary
This study demonstrates in situ focus characterization for extreme ultraviolet (XUV) free-electron laser sources. The new method achieves micrometer resolution for real-time monitoring and alignment of XUV optics.
Area of Science:
- Optics and Photonics
- Materials Science
- Laser Physics
Background:
- Characterizing focus in extreme ultraviolet (XUV) free-electron laser (FEL) experiments is crucial for precise measurements.
- Existing ex situ methods can be time-consuming and may not reflect real-time beam conditions.
Purpose of the Study:
- To develop and demonstrate an in situ technique for characterizing the focus of XUV FELs.
- To enable real-time monitoring and alignment of XUV focusing optics.
Main Methods:
- Utilized an ablation technique at an XUV FEL source.
- Designed an instrument capable of few-micrometer resolution while maintaining ultrahigh vacuum.
- Employed optically transparent samples like PMMA to visualize ablative imprints.
Main Results:
- Achieved high-contrast visibility of ablative imprints.
- Demonstrated on-line monitoring of beam profile changes.
- Observed good agreement between in situ imprint analysis and ex situ Nomarski microscopy.
Conclusions:
- The developed in situ method provides accurate focal characterization for XUV FELs.
- This technique facilitates efficient alignment of XUV focusing optics.
- It is suitable for micro-focus experiments requiring precise beam control.
