Surface-enhanced high-harmonic generation: a promising approach for extreme ultraviolet frequency combs

Area of Science:

• Quantum Optics
• Attosecond Science

Background:

• High-harmonic generation (HHG) is a key process for producing extreme ultraviolet (XUV) light.
• Controlling HHG spatially and spectrally is crucial for advanced applications.
• Surface enhancement offers a pathway to modify and improve HHG processes.

Purpose of the Study:

• To propose and investigate a scheme for producing XUV frequency combs.
• To utilize surface-enhanced optical fields for high-harmonic generation.
• To explore methods for controlling the emission properties of generated high harmonics.

Main Methods:

• Employing a surface-enhanced optical field to drive high-harmonic generation.
• Generating high harmonics within a wavelength-scale spatial region.
• Analyzing the angular emission probability of the generated harmonics.
• Investigating the effects of an additional static electric field and a polarization-gated scheme.

Main Results:

• High harmonics are generated in a confined, wavelength-scale region.
• A distinct emission probability is observed at an angle of approximately 10 degrees relative to the surface.
• Control over harmonic emission is demonstrated using static electric fields and polarization gating.
• Enhanced energy conversion efficiency and generation of even-order harmonics are achieved.

Conclusions:

• The proposed surface-enhanced HHG scheme is a promising method for generating XUV frequency combs.
• Spatial control of harmonic emission is feasible, offering new possibilities for tailoring XUV light.
• The integration of static electric fields or polarization gating provides enhanced control and efficiency.