A tunable broadband terahertz metamaterial absorber based on the vanadium dioxide

Structural Optimization and Performance Analysis of a Tunable Ultra‐Broadband Terahertz Absorber

“…Under vertical incidence, the absorber achieves broadband absorption of 3.50 THz with an absorption rate of more than 90% in the range of 2.47-5.97 THz, which is wider than the absorption bandwidth of other terahertz absorbers reported previously. [37][38][39][40][41][42][43][44][45][46] By changing the conductivity of vanadium dioxide from 0 to 200 000 S m À1 , the absorption intensity of the absorption peak of the absorber can be continuously and dynamically tuned from 3.90% to 99.75%, and an approximate perfect amplitude modulation can be achieved in a wide tuning range. Its absorption performance is much better than that of the absorbers based on vanadium dioxide previously reported.…”

“…The superposition of these two absorption peaks makes the absorber achieve a broadband absorption of more than 90% and a bandwidth of 3.50 THz from 2.47 to 5.97 THz, which is wider than the absorption bandwidth of other terahertz absorber reported previously. [37][38][39][40][41][42][43][44][45][46] The full width at half maximum (FWHM) is 5.29 THz, 122.28% relative to the central frequency. The absorption mechanism of the metamaterial absorber based on the coplanar arrangement of two rings with different sizes is different from that of the single-ring absorber mentioned earlier.…”

“…The results show that at the vertical incidence angle, the absorption bandwidth of the terahertz absorber with the absorption rate of 90% and above ranges from 2.47 to 5.97 THz, and the bandwidth reaches 3.50 THz, which is better than the previous report of the terahertz absorber based on vanadium dioxide. [37][38][39][40][41][42][43][44][45][46] The absorption performance of the absorber has been greatly improved here. By changing the temperature, the conductivity of vanadium dioxide is changed from 0 to 2 Â 10 5 S m À1 , that is, from the insulating phase to the metallic phase, which enables the absorption peak intensity to be dynamically tuned continuously from 3.90% to 99.75% with a wide tuning range, thus achieving approximately perfect amplitude modulation.…”

Review of Broadband Metamaterial Absorbers: From Principles, Design Strategies, and Tunable Properties to Functional Applications

“…The switching of a functional device using VO 2 by tuning the temperature between 300 and 350 K was proposed. [ 478 ] A broadband thermally tunable IR absorber based on the coupling of the standing wave and magnetic resonance was given, [ 96 ] which has an absorption bandwidth of up to 2.9 µm and a temperature tunable reflectivity in the range of 5–42%. By integrating VO 2 /SiO 2 /VO 2 nanopillar arrays on Al 2 O 3 substrates with W/VO 2 /W nanopillar arrays on W substrates, an IR BMA with dynamically tuned absorbance was presented by thermally induced VO 2 phase transition.…”

A Switchable Ultra-Wideband Metamaterial Absorber with Polarization-Insensitivity and Wide-incident Angle at THz Band

“…The geometrical parameter of the VO 2 disk is r 5 μm. During the simulation process, the VO 2 disk is set as a thermally tunable resistance film material with the conductivity σ 2 × 10 2 S/m when the temperature T 300 K and σ 2 × 10 5 S/m when temperature T 350 K according to the reference (Dao et al, 2019), the thickness of VO 2 disk is 3 μm. The polyimide dielectric substrate selected has a relative dielectric constant of ε r 2.35, a loss of tan δ 2.35 and its thickness is 7 μm.…”