Active terahertz metamaterials based on the phase transition of VO2 thin films

Abstract

Vanadium dioxide (VO 2 ) thin films were prepared on single crystal sapphire substrates by pulsed laser deposition. VO 2 films exhibited a significant resistivity drop (N 10 4 Ω-cm) and large optical transmittance change (N 60%) in the near-infrared region across their semiconductor-to-metal transition. Hybrid metamaterial devices designed for the THz frequency regime were fabricated by combining double split-ring resonators (SRRs) with phase changing VO 2 films. By changing the conductivity of VO 2 via temperature, the behavior of the SRR gap was adjusted from capacitive to resistive in order to modulate the THz beam transmission at their resonance frequencies. A modulation efficiency greater than 50% was achieved at the magnetic resonance frequencies (0.3 THz and 0.7 THz) in these hybrid SRR-VO 2 metamaterial devices.Published by Elsevier B.V.

Vanadium Oxide as a Key Constituent in Reconfigurable Metamaterials

“…Hybrid metamaterial devices operating at THz frequencies were fabricated by combining double SRRs with phase changing VO 2 films. By thermal triggering of the resistivity change of VO 2 , the behavior of the SRR gap can be adjusted from capacitive to resistive in order to modulate the THz beam transmission at their resonance frequencies [20][21][22][23].…”

Terahertz transmission properties of vanadium dioxide films deposited on gold grating structure with different periods

“…And the properties of grating structure can be controlled by period, fill factor or material of grating. Meanwhile, many changeable properties of MMs based THz modulator have been realized by introducing active materials such as vanadium dioxide (VO 2 ) [12][13][14][15], photonic crystals [16][17][18], polymer materials [19,20] and graphene [21,22]. In recent years, VO 2 has received increasing interest.…”

All-optical short pulse translation through cross-phase modulation in a VO_2 thin film

“…VO 2 thin films (200 nm) were deposited on c axis, single crystal sapphire substrates by pulsed laser deposition (PLD) [15][16][17]. Details of the deposition conditions of VO 2 thin film have been described elsewhere [5,17].…”

“…VO 2 thin films (200 nm) were deposited on c axis, single crystal sapphire substrates by pulsed laser deposition (PLD) [15][16][17]. Details of the deposition conditions of VO 2 thin film have been described elsewhere [5,17]. Briefly, a KrF excimer wlaser (Lambda Physik LPX 305, λ 248 nm, pulse duration 30 ns) was operated at a pulse rated of 10 Hz and was focused onto a rotating VO 2 target with a laser beam energy density of 1.5 J∕cm 2 and a target-to-substrate distance of 5.8 cm.…”

“…In order to allow optical transmissivity measurements, both sides polished sapphire substrates were used in this work. The deposited films exhibited a significant resistivity drop by four orders of magnitude and ∼60% optical transmittance drop at near IR (2500 nm) as the temperature increased up to 100°C above the transition temperature [17]. Figure 1 illustrates the fiber-optic experimental setup used to measure the transmission of the VO 2 sample in the 1550 nm optical communications wavelength window.…”