A multifunctional metasurface: from extraordinary optical transmission to extraordinary optical diffraction in a single structure

TL;DR

This paper demonstrates a metasurface capable of switching between extraordinary optical transmission and diffraction by tuning incident angles, enabling multifunctional optical device applications.

Contribution

It introduces an analytical model to control resonance pathways in a metasurface, allowing switching between EOT and EOD functionalities.

Findings

Achieved control over diffraction pathways via wavevector tuning.

Demonstrated multifunctional device switching between filter, mirror, and lens.

Provided a design framework for integrated optical devices.

Abstract

We show that, a metasurface composed of subwavelength metallic slit array embedded in an asymmetric environment can exhibit either extraordinary optical transmission (EOT) or extraordinary optical diffraction (EOD). By employing an analytical model expansion method and the diffraction order chart in k-vector space, we found that the resonance decaying pathway of the local slit cavity mode can be tuned to either 0th or -1st diffraction order by changing the parallel wavevector, which gives rise to enhanced 0th transmission (EOT) of the structure for small incident angles, and enhanced -1st diffraction (EOD) for large incident angles. Based on this appealing feature, a multifunctional metasurface that can switch its functionality between transmission filter, mirror and off-axis lens is demonstrated. Our findings provide a convenient way to construct multifunctional integrated optical devices on a single planar device.