Metasurface‐Empowered Optical Multiplexing and Multifunction

Abstract

Metasurfaces are planar photonic elements composed of subwavelength nanostructures, which can deeply interact with light and exploit new degrees of freedom (DOF) to manipulate optical fields. In the past decade, metasurfaces have drawn great interest from the scientific community due to their profound potential to arbitrarily control light. Here, recent developments of multiplexing and multifunctional metasurfaces, which enable concurrent tasks through a dramatic compact design, are reviewed. The fundamental properties, design strategies, and applications of multiplexing and multifunctional metasurfaces are then discussed. First, recent progress on angular momentum multiplexing, including its behavior under different incident conditions, is considered. Second, a detailed overview of polarization‐controlled, wavelength‐selective, angle‐selective, and reconfigurable multiplexing/multifunctional metasurfaces is provided. Then, the integrated and on‐chip design of multifunctional metasurfaces is addressed. Finally, future directions and potential applications are presented.

Meta-optics for spatial optical analog computing

“…Recent advances in achromatic focusing [93], computational imaging [94], and multiplane holography [95] promise the emergence of these platforms as new paradigms in computational systems. Moreover, recent development of multiplexed and multifunctional metasurfaces through integration of different information channels into a single or multilayered metasurfaces with segmented or interleaved metaatoms [96,97] could have deep impact on the future optical computation technology. Finally, integration of resonant metasurfaces with III-V compound semiconductors with strong adjustability helps shrinking the overall size of the photodetector arrays or even cameras in the last (or output) layer of an optical computing system.…”

Polarization‐Sensitive Dielectric Membrane Metasurfaces

“…[19] Encoding several distinct functionalities in a single meta surface could further improve the integration of complicated optical systems. [27][28][29][30] Metadevices combining several functionali ties could be versatile, extending the scope of potential applica tions for flatoptics components. One of the popular strategies for developing such metasurfaces is to employ multiplexing resonators that have different dimensions and orientations, including segmentation and interleaving.…”

“…One of the popular strategies for developing such metasurfaces is to employ multiplexing resonators that have different dimensions and orientations, including segmentation and interleaving. [27,30] Another efficient solution for applications is to use polarizationdependent meta surfaces. [31][32][33][34] By interleaving the device designs for orthogonal polarization states or designing the polarizationselective meta atom, such as elliptical and rectangular disks or holes, [35][36][37] a metasurface can show distinct functionalities under varying inci dent polarizations.…”

Optical vortex knots and links via holographic metasurfaces

“…Anisotropic metasurfaces, which work as nanoscale birefringent phaseshifters, in recent years have been substantially studied [74], showing application prospects in achromatic metalens [75], polarization-dependent holographic display [76], broadband response [77], and efficient optical devices [78] et al This artificially planar material enables the simultaneous modulation of local phase, amplitude, and polarization of light field in subwavelength scale, molds optical wavefront into arbitrary mode, providing a new possibility for the miniaturization and integration of modern optical devices [79][80][81][82][83]. Typically, various metasurfaces have been proposed with advantages in applications associated with optical vortex, such as OAM holography [84], multiplexing, and demultiplexing [85] et al…”