Electrically switchable 2^N-channel wave-front control for certain functionalities with N cascaded...

Area of Science:

• Optics and Photonics
• Materials Science
• Electrical Engineering

Background:

• Metasurfaces offer tunable optical functionalities crucial for advanced optical systems.
• Existing polarization-multiplexed metasurfaces have limitations in operating channel scalability.
• There is a need for increased channel capacity without compromising performance.

Purpose of the Study:

• To propose and demonstrate a scalable architecture for polarization-multiplexed metasurfaces.
• To achieve a significant increase in the number of electrically switchable channels.
• To validate the proposed structure for functionalities like beam steering and vortex beam generation.

Main Methods:

• Designed an N-layer cascaded dual-channel metasurface structure.
• Implemented a 3-layer prototype to achieve 8 switchable channels.
• Demonstrated functionalities including vortex beam generation and beam steering.

Main Results:

• Achieved 2^N electrically switchable channels with no intrinsic loss or cross-talk.
• Successfully implemented a 3-layer setup demonstrating 8 distinct optical channels.
• Showcased switchable topological charges for vortex beams (-3 to +4 or -1 to -8) and versatile beam steering patterns (8x1 line or 4x2 grid).

Conclusions:

• The proposed N-layer cascaded metasurface design offers a practical method to enhance scalability and functionality.
• This approach significantly expands the capabilities of polarization-multiplexed metasurfaces.
• Potential applications include LiDAR, 3D displays, OAM (de)multiplexing, and varifocal meta-lenses.