Non-orthogonal-polarization multiplexed metasurfaces for tri-channel gray-imaging

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Traditional polarization multiplexing uses orthogonal states, limiting information capacity.
• Metasurfaces offer novel ways to manipulate light polarization.
• Existing metasurface designs often require complex, multi-size nanostructures.

Purpose of the Study:

• To demonstrate tri-channel polarization multiplexing using metasurfaces in non-orthogonal states.
• To develop a single-size nanostructure design for polarization multiplexing.
• To achieve simultaneous recording of multiple images on a metasurface.

Main Methods:

• Utilizing nanostructured metasurfaces as pixel-by-pixel nano-polarizer arrays.
• Modulating incident light intensity via nanostructure orientation angles, governed by Malus's law.
• Integrating metasurfaces between bulk-optic polarizers and analyzers for controlled polarization combinations.

Main Results:

• Successfully implemented tri-channel polarization multiplexing in three non-orthogonal polarization states.
• Demonstrated simultaneous recording of a continuous gray-image and two independent binary patterns.
• Experimentally verified the concept by recording three independent gray-images directly on the metasurface.

Conclusions:

• Metasurfaces can achieve advanced polarization multiplexing beyond orthogonal states.
• The single-size nanostructure approach simplifies metasurface fabrication and design.
• This technology holds significant potential for optical storage, anti-counterfeiting, and information multiplexing due to its high information density and compactness.