Electromagnetic metasurface

1, “An alternative approach that has gained increasing attention in recent years deals with one- and two-dimensional (1D and 2D) plasmonic arrays with subwavelength periodicity, also known as metasurfaces.

Due to their negligible thickness compared to the wavelength of operation, metasurfaces can (near resonances of unit cell constituents) be considered as an interface of discontinuity enforcing an abrupt change in both the amplitude and phase of the impinging light”.

A highly absorbing ultrathin film on a substrate can also be considered as a metasurface, with properties not occurring in natural materials.

Subsequently, another important phenomenon, the Levi-Civita relation,[11] was introduced, which states that a subwavelength-thick film can result in a dramatic change in electromagnetic boundary conditions.

The results showed that a 0.3 nm thick film could absorb all electromagnetic waves across the RF, microwave, and terahertz frequencies.

[36][37] Applications for meta-waveguides such as integrated waveguide mode converters,[37] structured-light generations,[38][39] versatile multiplexers,[40][41] and photonic neural networks[42] can be enabled.

[44][45][46][47] For many optically based bioimaging devices, their bulk footprint and heavy physical weight have limited their usage in clinical settings.

[50] A simulation toolkit has been released online, enabling users to efficiently analyze metasurfaces with customized pixel patterns.