Quad-channel independent wavefront encoding with dual-band multitasking metasurface

Area of Science:

• Electromagnetics
• Materials Science
• Nanotechnology

Background:

• Achieving multiple electromagnetic (EM) functionalities on a shared aperture in dual frequency bands is crucial for many applications.
• Existing dual-band metasurfaces often suffer from limited channels or narrow bandwidths, hindering their practical implementation.
• There is a need for advanced metasurface designs that offer independent control over multiple EM functionalities across wide frequency bands and polarization states.

Purpose of the Study:

• To propose and demonstrate a novel reflective coding metasurface enabling four independent EM functionalities in quad-polarization channels across two wide frequency bands.
• To design meta-atoms capable of independent phase modulation for linear and circular polarizations at distinct frequencies.
• To validate the metasurface's capabilities through the design of a multifunctional metadevice integrating beam deflection, diffuse scattering, and vortex beam generation.

Main Methods:

• Design of a reflective coding metasurface utilizing quasi-I-shaped and cross-shaped metastructures for independent phase modulation.
• Integration of meta-atoms capable of controlling phase for orthogonal linear polarizations at low frequencies and decoupled circular polarizations at high frequencies.
• Fabrication and experimental/simulation validation of a multifunctional metadevice showcasing distinct wavefront tailoring in each polarization and frequency channel.

Main Results:

• Demonstration of a reflective coding metasurface with four independent EM functionalities in quad-polarization channels across two wide frequency bands.
• Achieved independent phase modulation for linear and circular polarizations at low and high frequencies, respectively, with low cross-talk.
• Experimental and simulation results confirmed distinct wavefront tailoring for beam deflection, diffuse scattering, and vortex beam generation in each channel.

Conclusions:

• The proposed multifunctional metasurface offers independent phase modulation across frequencies and polarizations, overcoming limitations of existing designs.
• This technology has the potential to unlock advanced metasurface capabilities for complete wavefront control, enabling EM function integration and multiple channel communication.
• The developed metasurface paves the way for applications in polarization optics, advanced antenna systems, and other areas requiring sophisticated EM control.