Attosecond beamline with actively stabilized and spatially separated beam paths.

Area of Science:

• Physics
• Spectroscopy
• Ultrafast Science

Background:

• Attosecond spectroscopy requires precise control over ultrashort laser pulses.
• Existing setups can be complex and lack long-term stability for attosecond timescale measurements.

Purpose of the Study:

• To present a versatile and compact beamline for attosecond spectroscopy.
• To achieve active stabilization of extreme-ultraviolet (XUV) and infrared (IR) pulse delays on the attosecond timescale.

Main Methods:

• Utilized a high-order harmonic source to generate XUV pulses.
• Implemented a delay line for spatial separation and recombination of XUV and infrared (IR) pulses.
• Developed a novel active-stabilization scheme using a helium-neon laser and white-light interferometer.

Main Results:

• Achieved accurate delay control with 26 attoseconds root-mean-square (rms) fluctuation over 1.5 hours.
• Enabled independent manipulation of XUV and IR pulse properties (intensity, polarization, frequency).
• Demonstrated imaging of the high-order harmonic generation region for both XUV and IR pulses into an interaction volume.

Conclusions:

• The developed beamline offers a stable and versatile platform for attosecond pump-probe spectroscopy.
• It facilitates the study of ultrafast dynamics in various states of matter (gases, liquids, solids).
• The independent pulse manipulation capabilities enhance experimental flexibility.