Broadband diffusion metasurface based on a single anisotropic element and optimized by the Simulated Annealing...

Area of Science:

• Metasurface design and electromagnetic applications.
• Nanophotonics and artificial materials.
• Wave manipulation and scattering control.

Background:

• Metasurfaces offer unique electromagnetic properties but designing for broadband and wide-angle diffusion remains challenging.
• Coding metamaterials provide a framework for controlling metasurface responses using discrete element states.
• Anisotropic structures are key to achieving polarization-dependent phase control.

Purpose of the Study:

• To propose a new strategy for designing broadband and wide-angle diffusion metasurfaces.
• To utilize anisotropic elements as binary states ('0' and '1') within a coding metamaterial framework.
• To achieve uniform backward scattering under normal incidence.

Main Methods:

• Employing anisotropic unit cells with opposite phase responses for x- and y-polarized incident waves.
• Utilizing the concept of coding metamaterial to arrange these elements.
• Applying the Simulated Annealing algorithm to optimize the element layout for uniform scattering.

Main Results:

• Demonstrated a simple yet efficient method for designing diffusion metasurfaces.
• Achieved broadband and wide-angle diffusion characteristics.
• Validated the design through both electromagnetic simulations and experimental measurements.

Conclusions:

• The proposed strategy enables effective design of diffusion metasurfaces with simple structures.
• The use of anisotropic elements and coding metamaterial principles leads to broadband and wide-angle performance.
• The Simulated Annealing algorithm is a viable tool for optimizing metasurface layouts for specific scattering properties.