Bandwidth broadening of a linear polarization converter by near-field metasurface coupling

Xi Gao,Haiou Li,Leena Singh,Weili Zhang,Wanli Yang,Jingjing Zheng

doi:10.1038/s41598-017-07296-4

Abstract

We experimentally demonstrate a highly efficient, broadband linear polarization converter functioning at terahertz frequencies. The linear polarization converter is composed of three metasurfaces and two dielectric layers interlaced with each other. The neighboring unit cells of the central metasurface layer of the linear polarization converter exhibit strong electromagnetic coupling, which increases the number of resonances and results in significant bandwidth broadening. The simulation and experimental results show that in the frequency range of 0.2 to 0.4 THz, the proposed polarization converter has a flat transmission curve and exhibits a transmission efficiency that is higher than 80%. High performance terahertz polarization conversion is desirable in many fields, such as terahertz spectroscopy, imaging, and communications.

Highlights

The rapid advancement of terahertz science has led to the development of many practical applications in the fields of imaging, sensing, communications, and biomedicine[1,2,3]
The polarization converters that function in transmission mode usually have the disadvantages of being narrowband and having a low polarization conversion efficiency
A few novel metasurfaces have been proposed to improve the performance of the transmission polarization converter[20, 21], achieving a high conversion efficiency over a broad bandwidth remains challenging

Summary

Introduction

The rapid advancement of terahertz science has led to the development of many practical applications in the fields of imaging, sensing, communications, and biomedicine[1,2,3]. A few novel metasurfaces have been proposed to improve the performance of the transmission polarization converter[20, 21], achieving a high conversion efficiency over a broad bandwidth remains challenging. To demonstrate the performance of the proposed polarization converter, we fabricated the sample and measured its transmission coefficient.

Results

Conclusion