Arbitrary birefringent metamaterials for holographic optics at λ = 155 μm

Abstract

This paper presents an optical element capable of multiplexing two diffraction patterns for two orthogonal linear polarizations, based on the use of non-resonant metamaterial cross elements. The metamaterial cross elements provide unique building blocks for engineering arbitrary birefringence. As a proof-of-concept demonstration, we present the design and experimental characterization of a polarization multiplexed blazed diffraction grating and a polarization multiplexed computer-generated hologram, for the telecommunication wavelength of λ = 1.55 μm. A quantitative study of the polarization multiplexed grating reveals that this approach yields a very large polarization contrast ratio. The results show that metamaterials can form the basis for a versatile and compact platform useful in the design of multi-functional photonic devices.

Investigation of the Structural, Electrical, and Optical Properties of the Nano-Scale GZO Thin Films on Glass and Flexible Polyimide Substrates

“…In the past, determination of the optical band gap ( Eg ) was often necessary to develop the electronic band structure of a thin-film material. However, using extrapolation methods, the Eg values of the GZO thin films can be determined from the absorption edge for direct interband transition, which can be calculated using the relation in Equation (3) as follows: αhν = C × (hν − Eg ) 1/2 where C is the constant for the direct transition, h is Planck’s constant, and ν is the frequency of the incident photon [ 19 ]; α is the optical absorption coefficient, which is calculated using Lambert’s law as follows: α = ln((1/ T )/ h ) where T and h are the thin film’s transmittance ratio and thickness.…”

Bifunctional gap-plasmon metasurfaces for visible light: polarization-controlled unidirectional surface plasmon excitation and beam steering at normal incidence

“…In recent years, optical metasurfaces, that is, optically thin planar arrays of resonant subwavelength elements arranged in a periodic or aperiodic manner, have attracted increasing attention because of their planar profiles and relative ease of fabrication while enabling unprecedented control over optical fields by modifying boundary conditions for impinging optical waves 1 , 2 , 3 , 4 . As such, numerous fascinating applications have been proposed, and promising ultra-compact devices have been accordingly demonstrated by designed metasurfaces, including beam-steering devices 5 , 6 , 7 , 8 , 9 , 10 , surface waves or waveguide couplers 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , focusing lenses 19 , 20 , 21 , 22 , 23 , optical holograms 24 , 25 , 26 , 27 , 28 , 29 , coding metasurfaces 30 , 31 , 32 , waveplates 33 , 34 , 35 , 36 and polarimeters 37 , 38 , 39 , 40 , 41 .…”

“…However, most state-of-the-art metasurfaces are designed for a single functionality or identical/similar functionalities (for example, polarization-dependent beam steering 9 , 10 , surface waves coupling 13 , 14 , 15 and holograms 24 , 27 , 28 , 29 ), not quite reaching the desired goal of realizing distinctly different functionalities. Metasurfaces that facilitate efficient integration of multiple diversified functionalities into a single ultrathin device with a compact footprint have become an emerging research area.…”

Full-color hologram using spatial multiplexing of dielectric metasurface

“…Taking advantage of recently developed metasurfaces to imprint abrupt interfacial phase changes at subwavelength scale [3][4][5][6], great achievements such as wideangle projection, elimination of high-order diffraction, and broadband spectral response have been made toward promising applications for optical trapping [7], quantum optics [8], and integrated photonics [9]. However, most existing metasurface holograms can only reconstruct monochromatic images [10][11][12][13][14][15][16], which strongly limits their practical applications. To date, only a few research efforts have been conducted to construct metasurfaces having multicolor responses [17,18], and some issues such as the nontrivial spatial alignment, color crosstalk, low fidelity, and color mismatch between the hologram and computer display colorimetric systems have not been stressed yet.…”