Dynamically adjustable asymmetric transmission and polarization conversion for linearly polarized terahertz wave*

Abstract

The asymmetric transmission (AT) and polarization conversion of terahertz (THz) wave play a vital role in future THz communication, spectrum, and information processing. Generally, it is very difficult and complicated to actively control the AT of electromagnetic (EM) wave by using traditional devices. Here, we theoretically demonstrate a stereo-metamaterial (stereo-MM) consisting of a layer of metal structure and a layer of phase transition structure with a polyimide spacer in between. The performance of the device is simulated by using the finite-integration-technology (FIT). The results show that the AT and polarization conversion of linearly polarized wave can be dynamically controlled in a range of 1.0 THz–1.6 THz when the conductivity σ of vanadium dioxide (VO2) is changed under the external stimulation. This study provides an example of actively controlling of the AT and polarization conversion of the EM wave.

Broadband asymmetric transmission for linearly and circularly polarization based on sand-clock structured metamaterial*

“…[21][22][23][24][25][26] Even tunable AT using new materials, such as graphene, [27] VO 2 , [28] omegashaped metamaterial, [29] and Dirac semimetals, [30] was presented in the last several years. [31][32][33] However, few works reported a broadband diode like AT for linearly and circularly polarized waves in terahertz regions.…”

Multi-band asymmetric transmissions based on bi-layer windmill-shaped metamaterial*

“…[14] In addition, metamaterials have been used to realize perfect absorption, circular dichroism, optical activity, and the asymmetric transmission (AT) effect. [15][16][17][18][19][20] In recent decades, the AT effect has garnered increasing attention. To realize outstanding and tunable AT ef-fects in linearly and circularly polarized plane waves, several studies have been conducted, such as changing the shapes of symmetry-broken chiral metastructures, [21,22] increasing the layers of the proposed nanobars, [23,24] and tilting the rectangular nanoholes.…”

“…To realize outstanding and tunable AT ef-fects in linearly and circularly polarized plane waves, several studies have been conducted, such as changing the shapes of symmetry-broken chiral metastructures, [21,22] increasing the layers of the proposed nanobars, [23,24] and tilting the rectangular nanoholes. [25] With regard to circularly polarized plane waves, high-efficiency broadband and dualband AT effects have been studied and realized from microwave to optical regimes, [20,[26][27][28] and tunable AT effects have also been realized by integrating the graphene layers with metamaterials. [29][30][31] With regard to linearly polarized plane waves, several studies have focused on enhancing the efficiency and broadening the band of the AT effect.…”