A study on the electromagnetic mechanism of a flexible terahertz toroidal dipole metasurfaces

Abstract

We have designed and fabricated metasurfaces structures generated toroidal dipole phenomenon by fabricating periodic metal pattern on polyimide substrate. The metasurfaces structure consists of two symmetric split rings along the Y-axis.The impact of structural parameters, gap, and SR, on the electromagnetic characteristics of metasurfaces at terahertz frequencies was investigated. An increase in gap results in a blue shift phenomenon in the amplitude transmission spectrum, while an increase in SR leads to a red shift phenomenon in the amplitude transmission spectrum.The intrinsic mechanism of the toroidal resonance is investigated more deeply by calculating the multipole scattering power and Q-factor. Q-factor values of 2.3 and 9.5 were obtained at low and high frequencies, respectively. Terahertz toroidal dipole metasurfaces made on flexible substrates like this have the potential for applications in terahertz functional devices, such as sensors and tuners.

VO2-Based metasurface for dynamically tunable terahertz surface plasmonic waves

“…Metasurfaces, composed of subwavelength structures, are two-dimensional artificial materials exhibiting extraordinary capabilities in manipulating electromagnetic waves. They can precisely control the propagation characteristics of electromagnetic waves, including phase, amplitude, polarization, and direction, surpassing the limitations of traditional materials [6][7][8][9][10][11][12][13][14][15]. So far, metasurfaces have emerged as a critical tool in manipulating SPWs in the terahertz frequency range, offering new possibilities in advanced material and device engineering.…”