Ultrathin 90-degree sharp bends for spoof surface plasmon polaritons

Area of Science:

• Electromagnetism
• Materials Science
• Nanotechnology

Background:

• Surface waves can be confined on structured metal surfaces at low frequencies, enabling compact electromagnetic guiding devices.
• Spoof surface plasmons (SSPs) are electromagnetic waves confined to periodically structured metal surfaces, mimicking plasmon behavior at lower frequencies.

Purpose of the Study:

• To propose and demonstrate a method for highly efficient transmission of spoof surface plasmons around 90-degree sharp bends.
• To reduce scattering and suppress reflection in these waveguide bends using structural engineering.

Main Methods:

• Designing the dispersion relation of the structured metallic film to minimize scattering.
• Implementing structural decoration at the bending corner to suppress reflection.
• Employing a one-dimensional scattering theory to analyze transmission properties.

Main Results:

• Achieved highly efficient transmission of spoof surface plasmons around sharp bends.
• Demonstrated reduced scattering through engineered dispersion relations.
• Successfully suppressed reflection via structural modifications at the bend.

Conclusions:

• The proposed design enables efficient guiding of spoof surface plasmons around sharp bends in the microwave regime.
• The approach is versatile and applicable to other guiding components on two-dimensional metal surfaces.