THz filter based on the Si microdisk array

Jingjing Wang,Zhongyi Guo,Kai Guo

doi:10.1063/1.5083004

Abstract

Compared to plasmonic metasurface, all-dielectric metasurface can suppress radiation loss at terahertz (THz) frequencies due to the low intrinsic loss of dielectric. Here, we propose a THz filter based on all-dielectric metasurface composed of Si microdisk (SiMD) array standing on TPX substrate. Numerical simulation results demonstrate that both electric dipole and magnetic dipole resonances are excited in the SiMD, resulting in a high reflection coefficient of 100%. The working frequency of the designed filter can be passively tuned over a wide range from 1.0 THz to 1.5 THz by manipulating the radius of the SiMD. In addition, the proposed filter is robust to the incident polarizations (x-/y-linear polarizations) and the incident angles (ranging from 0° to 25°). Besides, a new degree of freedom is introduced by cutting a split in the SiMD. The filter can work well even with a split in the SiMD since the presence of the split does not induce additional losses. We further demonstrate the resonant modes can also be modified by tuning the width of the splitting gap, resulting in a tunable THz filter with high efficiency.

Highlights

Terahertz (THz) technology, a cutting-edge research field, promises a series of wonderful applications, ranging from scanners in airport security, non-destructive inspection and quality control to bio-imaging, bio-sensing, high speed communication and astronomy.1 All these potential applications are based on the unique properties of THz wave, which combines the advantages of both microwave and infrared waves.2 further applications are restricted by the weak interaction between the THz waves and natural materials
We propose a THz filter based on reflective alldielectric metasurface composed of crystal Si microdisk (SiMD) array, achieving reflection coefficient close to 100%
We have proposed a THz filter based on alldielectric metasurface, which consists of SiMD array embedded on TPX substrate

Summary

INTRODUCTION

Terahertz (THz) technology, a cutting-edge research field, promises a series of wonderful applications, ranging from scanners in airport security, non-destructive inspection and quality control to bio-imaging, bio-sensing, high speed communication and astronomy. All these potential applications are based on the unique properties of THz wave, which combines the advantages of both microwave and infrared waves. further applications are restricted by the weak interaction between the THz waves and natural materials. Metasurface can manipulate optical phase covering an entire circle (0-2π) by changing the geometry of individual resonators, shaping the outgoing wavefront in transmission and reflection.21,22 These functions are more common in visible and infrared light. With the rapid developments of THz technology, people have recently proposed many metasurface based devices to control THz waves, such as modulators, polarizers, filters, absorbers, detectors, and sensors.. With the rapid developments of THz technology, people have recently proposed many metasurface based devices to control THz waves, such as modulators, polarizers, filters, absorbers, detectors, and sensors.29,30 Most of these all-dielectric are designed to realize THz perfect absorbers and transmissive filters. The obtained results demonstrate the great potential of our designed metasurfaces for designing functional devices in the THz range

STRUCTURAL DESIGN OF THE T

Findings

CONCLUSION