TY - JOUR

T1 - A Focusing Circular-Polarization THz Beam Splitter Based on a Self-Complementary Metasurface

AU - Lenets, Vladimir A.

AU - Kuznetsov, Sergei A.

AU - Sayanskiy, Andrey D.

AU - Lazorskiy, Pavel A.

AU - Baena, Juan D.

AU - Glybovski, Stanislav B.

N1 - Publisher Copyright: © 2011-2012 IEEE. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/3

Y1 - 2021/3

N2 - Quasi-optical polarization beam splitters are important components of terahertz instrumentation widely used in interferometric and polarimetric measurements. Recently metasurfaces, i.e., two-dimensional periodic or quasi-periodic optically dense structures composed of unit cells with subwavelength dimensions, have been shown to operate as compact and efficient beam splitters. Typically, their design was based on careful optimization of anisotropic metal or dielectric resonant scatterers confined in each unit cell. In this work, we propose and experimentally demonstrate a simple and useful approach to designing circular-polarization beam splitters taking advantage of intrinsically frequency-independent properties of single-layer self-complementary metasurfaces (SCMSs). Theoretically, when illuminated with a circularly polarized beam, any SCMS at any frequency transmits a copolarized beam with a complex transmission coefficient of 1/2. At the same time, a cross-polarized beam of the same magnitude is produced, with a transmission phase that can be controlled at every point of a metasurface aperture. In this work, to split the copolarized and cross-polarized transmitted beams, we spatially modulate this phase by constructing a spatially nonuniform metasurface of self-complementary unit cells. With this approach, we experimentally demonstrate a focusing circular-polarization beam splitter operating near 0.345 THz.

AB - Quasi-optical polarization beam splitters are important components of terahertz instrumentation widely used in interferometric and polarimetric measurements. Recently metasurfaces, i.e., two-dimensional periodic or quasi-periodic optically dense structures composed of unit cells with subwavelength dimensions, have been shown to operate as compact and efficient beam splitters. Typically, their design was based on careful optimization of anisotropic metal or dielectric resonant scatterers confined in each unit cell. In this work, we propose and experimentally demonstrate a simple and useful approach to designing circular-polarization beam splitters taking advantage of intrinsically frequency-independent properties of single-layer self-complementary metasurfaces (SCMSs). Theoretically, when illuminated with a circularly polarized beam, any SCMS at any frequency transmits a copolarized beam with a complex transmission coefficient of 1/2. At the same time, a cross-polarized beam of the same magnitude is produced, with a transmission phase that can be controlled at every point of a metasurface aperture. In this work, to split the copolarized and cross-polarized transmitted beams, we spatially modulate this phase by constructing a spatially nonuniform metasurface of self-complementary unit cells. With this approach, we experimentally demonstrate a focusing circular-polarization beam splitter operating near 0.345 THz.

KW - Beam Splitter

KW - Focusing

KW - Metasurface

KW - Polarization

KW - Terahertz

KW - terahertz (THz)

KW - metasurface (MS)

KW - polarization

KW - Beam splitter

KW - focusing

UR - http://www.scopus.com/inward/record.url?scp=85096395547&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/f0e7de9f-ab1c-39d8-8ea6-6322dc007846/

U2 - 10.1109/TTHZ.2020.3036191

DO - 10.1109/TTHZ.2020.3036191

M3 - Article

AN - SCOPUS:85096395547

VL - 11

SP - 165

EP - 174

JO - IEEE Transactions on Terahertz Science and Technology

JF - IEEE Transactions on Terahertz Science and Technology

SN - 2156-342X

IS - 2

M1 - 9250679

ER -