Localized spoof surface plasmons in textured open metal surfaces

Area of Science:

• Physics
• Materials Science
• Electrical Engineering

Background:

• Conventional spoof-localized surface plasmons (spoof-LSPs) are typically supported by textured closed metal surfaces.
• These conventional spoof-LSPs arise from the interference of propagating surface modes.
• Understanding alternative mechanisms for spoof-LSP generation is crucial for developing new plasmonic devices.

Purpose of the Study:

• To experimentally demonstrate spoof-LSPs on textured open metal surfaces.
• To investigate the mechanism behind spoof-LSPs on open metal surfaces.
• To explore the tunability of these spoof-LSP resonators.

Main Methods:

• Fabrication of ultrathin fan-shaped metallic strips with textured open surfaces.
• Experimental characterization of spoof-LSPs in the microwave frequency regime.
• Direct imaging of near-field response spectra and mode profiles.

Main Results:

• Textured open metal surfaces support spoof-LSPs in microwave frequencies.
• Spoof-LSPs on open surfaces originate from Fabry-Perot-like resonances, distinct from closed surfaces.
• The number of modes and resonance frequencies are tunable by altering the grating number or length of the fan-shaped strips.

Conclusions:

• Textured open metal surfaces offer a new platform for spoof-LSPs.
• Fabry-Perot-like resonances provide a simplified design approach for spoof-plasmonic resonators.
• The length of the fan-shaped metallic strip is a single degree of freedom for tuning spoof-plasmonic devices.