Polarization Multiplexing Terahertz Quasicrystal Meta-Platform

Area of Science:

• Optics and Photonics
• Metamaterials
• Terahertz (THz) Technology

Background:

• Multidimensional metasurfaces are key for terahertz (THz) applications like communication, imaging, and sensing.
• Existing metallic or periodic metasurfaces face challenges including ohmic loss, diffraction, crosstalk, and energy leakage.
• There is a need for advanced metasurface designs to overcome these limitations for improved THz device performance.

Purpose of the Study:

• To propose and validate an all-dielectric THz metasurface utilizing a quasicrystalline aperiodic tiling.
• To demonstrate independent wavefront control for orthogonal polarizations within a single aperture.
• To achieve polarization-multiplexed bifocal focusing with controllable focal positions.

Main Methods:

• Design of an all-dielectric metasurface using high-resistivity silicon rectangular pillars as anisotropic meta-atoms.
• Implementation of a five-fold rotationally symmetric quasicrystalline aperiodic tiling.
• Full-wave electromagnetic simulations to verify performance and analyze characteristics.

Main Results:

• The proposed quasicrystalline metasurface enables independent phase encoding for x- and y-polarized light.
• Demonstrated polarization-multiplexed bifocal focusing with controllable focal positions.
• Simulation results indicate high focusing efficiency, low polarization crosstalk, broadband performance, and robustness to oblique incidence.

Conclusions:

• The developed all-dielectric quasicrystalline metasurface offers a compact and efficient solution for THz wavefront control.
• This approach effectively addresses limitations of conventional metallic metasurfaces.
• The design provides a promising route for multifunctional THz devices leveraging polarization multiplexing and aperiodic tiling.