Epsilon-near-zero nonlinearity enhancement in the extreme ultraviolet

Area of Science:

• Nonlinear Photonics
• Plasmonics
• Materials Science

Background:

• Vanishing dielectric constant materials enable plasmon-enhanced light-matter interactions.
• These materials are crucial for nonlinear photonics applications.
• Extreme ultraviolet (XUV) light interactions often exhibit weak nonlinearities.

Purpose of the Study:

• To experimentally demonstrate XUV plasmon-enhanced self-driven spectral modification.
• To utilize tunable Ferrell-Berreman epsilon-near-zero resonances in aluminum.
• To achieve efficient spectral modification at low peak intensities.

Main Methods:

• Excitation of epsilon-near-zero resonances in submicrometric aluminum foil.
• Utilizing angle-dependent measurements to analyze spectral modulation.
• Employing theoretical analysis to support experimental findings.

Main Results:

• First experimental demonstration of XUV plasmon-enhanced spectral modification.
• Efficient spectral modification achieved at peak intensities as low as 380 GW/cm².
• Attribution of enhancement to ultrafast heating and saturation effects.

Conclusions:

• Breakthrough in enhancing weak nonlinearities in the XUV regime via nonlinear plasmonics.
• Demonstration of efficient spectral modification with low absorption.
• Potential for new tools for XUV radiation manipulation and control.