Broadband terahertz transmissive quarter-wave metasurface

Xiaolong You; Rajour T. Ako; Wendy S. L. Lee; Madhu Bhaskaran; Sharath Sriram; Christophe Fumeaux; Withawat Withayachumnankul

doi:10.1063/5.0017830

APL Photonics (Sep 2020)

Broadband terahertz transmissive quarter-wave metasurface

Xiaolong You,
Rajour T. Ako,
Wendy S. L. Lee,
Madhu Bhaskaran,
Sharath Sriram,
Christophe Fumeaux,
Withawat Withayachumnankul

Affiliations

Xiaolong You: Terahertz Engineering Laboratory, School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide SA 5005, Australia
Rajour T. Ako: Functional Materials and Microsystems Research Group and The Micro Nano Research Facility, RMIT University, Melbourne VIC 3001, Australia
Wendy S. L. Lee: Terahertz Engineering Laboratory, School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide SA 5005, Australia
Madhu Bhaskaran: Functional Materials and Microsystems Research Group and The Micro Nano Research Facility, RMIT University, Melbourne VIC 3001, Australia
Sharath Sriram: Functional Materials and Microsystems Research Group and The Micro Nano Research Facility, RMIT University, Melbourne VIC 3001, Australia
Christophe Fumeaux: Terahertz Engineering Laboratory, School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide SA 5005, Australia
Withawat Withayachumnankul: Terahertz Engineering Laboratory, School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide SA 5005, Australia

DOI: https://doi.org/10.1063/5.0017830
Journal volume & issue: Vol. 5, no. 9
pp. 096108 – 096108-9

Abstract

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Polarization conversion devices are key components in spectroscopy and wireless communications systems. Conventional terahertz waveplates made of natural birefringent materials typically suffer from low efficiency, narrow bandwidth, and substantial thickness. To overcome the limitations associated with conventional waveplates, a terahertz quarter-wave metasurface with enhanced efficiency and wide bandwidth is proposed. The transmissive quarter-wave metasurface is rigorously designed based on an extended semi-analytical approach employing network analysis and genetic algorithm. Simulation results suggest that the design can achieve linear-to-circular polarization conversion with a 3-dB axial ratio relative bandwidth of 53.3%, spanning 205 GHz–354 GHz. The measurement results confirm that the proposed design enables a 3-dB axial ratio from 205 GHz to at least 340 GHz with a total efficiency beyond 70.2%, where the upper frequency bound is limited by the available experimental facility. This quarter-wave metasurface can cover an entire terahertz electronics band and can be scaled to cover other nearby bands under the same convention, which are technologically significant for future portable systems.

Published in APL Photonics

ISSN: 2378-0967 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Technology: Engineering (General). Civil engineering (General): Applied optics. Photonics
Website: https://aplphotonics.aip.org

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