Material platforms for optical metasurfaces

Abstract

Optical metasurfaces are judicously engineered electromagnetic interfaces that can control and manipulate many of light’s quintessential properties, such as amplitude, phase, and polarization. These artificial surfaces are composed of subwavelength arrays of optical antennas that experience resonant light-matter interaction with incoming electromagnetic radiation. Their ability to arbitrarily engineer optical interactions has generated considerable excitement and interest in recent years and is a promising methodology for miniaturizing optical components for applications in optical communication systems, imaging, sensing, and optical manipulation. However, development of optical metasurfaces requires progress and solutions to inherent challenges, namely large losses often associated with the resonant structures; large-scale, complementary metal-oxide-semiconductor-compatible nanofabrication techniques; and incorporation of active control elements. Furthermore, practical metasurface devices require robust operation in high-temperature environments, caustic chemicals, and intense electromagnetic fields. Although these challenges are substantial, optical metasurfaces remain in their infancy, and novel material platforms that offer resilient, low-loss, and tunable metasurface designs are driving new and promising routes for overcoming these hurdles. In this review, we discuss the different material platforms in the literature for various applications of metasurfaces, including refractory plasmonic materials, epitaxial noble metal, silicon, graphene, phase change materials, and metal oxides. We identify the key advantages of each material platform and review the breakthrough devices that were made possible with each material. Finally, we provide an outlook for emerging metasurface devices and the new material platforms that are enabling such devices.

High-Efficiency, Broadband, Near Diffraction-Limited, Dielectric Metalens in Ultraviolet Spectrum

“…Optical losses are minimized to a significant extent by choosing a wide bandgap and high refractive index dielectric material. Thus, dielectric metalenses outperform the plasmonic metalenses in terms of transmission applications [36]. The desired characteristics of dielectric metalenses comprise high diffraction and transmission efficiencies, large numerical aperture (NA), and broadband wavelength operation [37].…”

Nano-fabrication and characterization of silicon meta-surfaces provided with Pancharatnam-Berry effect

“…Since then, complementary efforts have been made to extent the PB phase concept realizing metasurfaces made of dielectric materials [17], which can have low or negligible absorption losses depending on the material and operating wavelength. To date, a wide range of dielectric materials have been studied and implemented in metasurfaces at visible regime, for example titanium oxide and silicon nitride [18].…”

Dynamic control of mode modulation and spatial multiplexing using hybrid metasurfaces

“…Metasurfaces have emerged as promising candidates for transforming the interactions between electromagnetic waves and matter [1][2][3][4]. By utilizing the arbitrary design freedom of metasurfaces to tailor the amplitude, phase, and polarization response, it might be possible to provide a flexible and compact platform to realize all types of functional devices, such as beam deflector, polarization converter, phase modulator, image processor and so forth [5][6][7][8][9][10][11][12].…”