Anisotropic meta-mirror for achromatic electromagnetic polarization manipulation

Abstract

Polarization states are of particular importance for the manipulation of electromagnetic waves. Here, we proposed the design and experimental demonstration of anisotropic meta-mirror for achromatic polarization tuning. It is demonstrated that linear polarized wave can be achromatically transformed to its cross-polarization state or to arbitrary circular polarization after its reflection from the mirror. Microwave experiments verified that the fraction bandwidth for 90% transformation efficiency can be larger than 3:1. Furthermore, by utilizing photoinduced carrier generation in silicon, a broadband tunable circular polarizer is demonstrated in the terahertz regime. V

Broadband anomalous reflection based on gradient low-Q meta-surface

“…Since the bandwidth of metamaterial is often limited by its resonant characteristic, techniques such as gradient multilayer and dispersion engineering are typically utilized to extend the working bandwidth. [18][19][20] For anomalous reflection/refraction, broadband performance has been demonstrated to be possible through cross-polarized scattering from V-shaped array. 21 Nevertheless, the scattered light possesses different polarization with the incident one and the efficiency is low (upper limit is estimated to ∼10%) because the V-shaped structure supports both anomalous and normal reflected/refracted beams.…”

“…It is chosen because its frequency dispersion can be easily tuned by changing the effective capacitance and inductance. 17,20 The incident electric field is polarized along y direction, thus the meta-surface can be treated as an impedance sheet with Z y (ω). The reflection phase y can be controlled by changing Z y and (or) the permittivity of the top layer.…”

Color display and encryption with a plasmonic polarizing metamirror

“…The detailed derivation about how to preserve spin state in metamirrors has been analyzed in previous works [28][29][30][31]. It should be remembered that a 180° phase difference between the two linearly polarized (LP) components along the x and y directions (Φ x and Φ y ) is necessary at normal incidence.…”

Broadband Metamaterial Reflectors for Polarization Manipulation Based on Cross/Ring Resonators

“…In recent years, metamaterials have provided various choices for polarization manipulation [1][2][3][4][5]. Based on anisotropy or optical activity, the linearly polarized incident wave can be converted to its cross polarized or circularly polarized wave by metamaterials [6][7][8][9]. For instance, cross polarization converters have been designed by the anisotropic high impedance surfaces which could cause different phase delays for different polarization waves [8], [9].…”