Terahertz Reconfigurable Metasurface for Dynamic Non-Diffractive Orbital Angular Momentum Beams using Vanadium Dioxide

Abstract

Orbital angular momentum (OAM) generation based on metasurfaces has attracted tremendous interest due to its potential in capacity enhancement of high-speed wireless communication systems. Reconfigurability is one of the key desired characteristics for the design of future metasurfaces. In this paper, a metasurface taking advantage of vanadium dioxide (VO 2) is proposed. The proposed design can generate a non-diffractive OAM beam and achieve the multiple reconfigurability of the topological charge, beam radius, beam deflection angle. The operation frequency can be adjusted by controlling the state of VO 2 at terahertz (THz) region. Simulation results demonstrate that the designed metasurface can generate a non-diffractive OAM beam with tunable topological charge and beam radius, propagating along ±x or ±y directions with the controllable deflection angle between 6.74°and 44.77°, ranging from 0.69 THz to 0.79 THz.

Optical Singularity Built on Tiny Holes

“…The transmission behavior of V‐shaped hole can be also explained by the coupling of the excited symmetric and asymmetric modes. Other resonant units including L‐shaped nanoholes [ 51 ] and C‐shaped holes [ 52 ] also show good controllability of the resonant phase.…”

“…The similar design may be realized by using the V‐shaped nanoantennas, [ 49 ] C‐shaped nanoholes [ 52 ] and U‐shaped nanoholes. Figure 6b shows the nanostructure consisting of rotated U‐shaped nanoholes and the introduced P–B phase combines a spiral phase and a gradient phase.…”

Light‐controllable energy‐saving and control overhead‐saving metasurface based on photoresistor

“…2 The wideranging applications of these materials, spanning from low microwave to optical frequencies, include shielding, lowreflective materials, antennas, electronic switches, resonators, and Terahertz communication, among others. 3,4 Recently, several significant advancements have been made in the field of metasurfaces. Li et al 5 proposes hybrid dispersion-engineered metamirrors that exhibit versatile dispersion manipulation.…”

“…This characteristic opens up the possibility of developing low‐loss structures with improved efficiency 2 . The wide‐ranging applications of these materials, spanning from low microwave to optical frequencies, include shielding, low‐reflective materials, antennas, electronic switches, resonators, and Terahertz communication, among others 3,4 . Recently, several significant advancements have been made in the field of metasurfaces.…”

Mode‐switchable orbit angular momentum waves by mechanically rotating 2 bit phase quantization transmitarray

“…However, the feed network tends to be much more complex as the total number of controlled OAM modes increases, while the complicated feed network produces high costs and serious divergence between different OAM modes, which makes them limited in practical applications. (2) Reconfigurable MSs by varactor diodes, PIN diodes or employing tunable metaparticles (such as vanadium dioxide, 19 graphene, 20 liquid crystal, 21 etc.). With low profile, low cost and simple feed structure, the 1‐bit or 2‐bit reflective programable MSs are proposed by using reconfigurable units integrated with the voltage‐controlled varactor diodes or PIN diodes 22 .…”