Terahertz Beam Splitter Based on I-Shaped Metasurface

Abstract

A linear polarization beam splitter operating in terahertz band is proposed and experimentally verified in this paper. The unit cell of the beam splitter is composed of the top "I" type metal pattern, the middle dielectric layer, and the bottom metal layer. Each subarray structure of the device consists of four unit cells that rotate progressively at an angle of 45 •. The horizontal and vertical sub-arrays form the gradient metasurface of 4 × 4. The incident linear polarized terahertz wave is reflected by the device and divided into four beams with approximately equal power, while having different propagating directions in the 0.18-0.30 THz band. The proposed terahertz beam splitter has the advantages of small size, low cost, and easy processing, and it can be applied to terahertz stealth and terahertz imaging.

Achromatic Dielectric Metasurface with Linear Phase Gradient in the Terahertz Domain

“…Even though some of metasurface based devices have similar functions near the design frequency, the intrinsic chromatic aberration [ 22 ] impedes the utility of these devices in many broadband scenarios. Taking the commonly used beam splitter [ 23,24 ] as an example, the reported terahertz circular‐polarization beam splitter, [ 25 ] all dielectric splitter with variable split ratio, [ 26 ] terahertz beam splitter based on I‐shape metasurface [ 27 ] and optically controlled dynamic splitter, [ 28 ] though work in broadband, produce significantly different steering angles in different frequencies resulting from chromatic aberration.…”

Recent Advances in Terahertz Manipulations Using C‐Shape‐Split‐Ring‐Resonator Metasurfaces (Review)

“…In the context of manipulating THz waves, metasurfaces have demonstrated tremendous potential. [55,56] Researchers have proposed various THz metasurfaces utilizing different elements such as metal rods, [57,58] grids, and patches, [59] C-shape-split-ring resonators (CSRRs), [60] V-shape resonators, [61] all-dielectric structures, [62,63] and photonic crystals. [64] Among these, metasurfaces based on CSRRs have gained particular popularity and widespread adoption in the THz frequency range.…”

Metasurfaces Excited by an Evanescent Wave for Terahertz Beam Splitters with a Tunable Splitting Ratio

“…A metasurface made of silicon cylinders enables the THz beam splitting with variable ratios [23]. The metasurface consisting of a sandwiched metal-dielectric-metal I-shaped pattern can reflect the incident polarized THz wave into having four beams [24]. In the existing designs, the splitting ratio is fixed after the beam splitter is fabricated and cannot be adjusted according to the varying demand in practice, which limits its applications [21][22][23][24].…”