Asymmetric surface wave excitation through metasurface-edge diffraction

Area of Science:

• Electromagnetism
• Metamaterials
• Surface Physics

Background:

• Selective excitation of surface waves is crucial for advanced wave devices.
• Existing methods face challenges in controlling localized surface wave modes.
• Metasurfaces offer tunable electromagnetic properties.

Purpose of the Study:

• To demonstrate how metasurface truncation can control surface wave excitation.
• To break spatial inversion symmetry for selective surface wave generation.
• To investigate the role of anisotropy and edges in surface wave coupling.

Main Methods:

• Utilizing a discrete Wiener-Hopf technique for exact scattering solutions.
• Analyzing the effect of metasurface truncation on surface wave modes.
• Combining large anisotropy with an edge for wave coupling.

Main Results:

• Metasurface truncation effectively breaks spatial inversion symmetry.
• An anisotropic metasurface with an edge couples plane waves to surface waves.
• Inverting the wavevector component parallel to truncation excites two distinct surface waves.

Conclusions:

• Metasurface truncation is a viable strategy for selective surface wave excitation.
• This approach enhances control over bound-wave and leaky-wave devices.
• The findings offer new design principles for metamaterial-based wave manipulation.