Two-dimensional reversed Cherenkov radiation on plasmonic thin-film

Area of Science:

• Optics and Photonics
• Materials Science
• Electromagnetism

Background:

• Reversed Cherenkov radiation is a phenomenon of significant research interest due to its unique properties and potential applications.
• Previously, reversed Cherenkov radiation was exclusively associated with left-handed metamaterials (double negative mediums).

Purpose of the Study:

• To demonstrate the generation of reversed Cherenkov radiation on plasmonic thin-films.
• To investigate the controllable characteristics of reversed Cherenkov radiation in different spectral regions.

Main Methods:

• Experimental achievement of reversed Cherenkov radiation on metamaterial thin-films (terahertz) and metal thin-films (visible light).
• Theoretical analysis and simulations to understand the underlying physics.
• Investigation of the relationship between radiation frequency, direction, and surface mode excitation.

Main Results:

• Successful generation of reversed Cherenkov radiation on both metamaterial and metal thin-films.
• Demonstrated controllability of radiation frequencies and directions.
• Established an inverse relationship between wavelength and frequency for reversed Cherenkov radiation, contrasting with normal Cherenkov radiation.

Conclusions:

• Reversed Cherenkov radiation can be generated on plasmonic thin-films, not just in metamaterials.
• The excitation of forward or backward surface modes on plasmonic thin-films determines the generation of normal or reversed Cherenkov radiation.
• This finding expands the possibilities for utilizing reversed Cherenkov radiation in various applications.