Manipulating polarization and electromagnetically induced transparency in a switchable metamaterial

In this paper, a broadband plasmon-induced transparency (PIT) hybrid metamaterial system (HMS) is realized and numerically demonstrated via the interference between different resonance modes of metal and dielectric resonators. The employed PIT HMS supports a strong near-fired coupling between unit cells consisting of eight TiO 2 nested split rings (dark plasmonic resonators) surrounded by four metal cut wires (bright plasmonic resonators) embedded in the intermediate dielectric layer, and a broad transparency window which is higher than 0.9 is obtained from 0.61 to 0.76 THz with a relative bandwidth of 21.9%. In the transparent window, the drastic change of phase leads to high group delay, and the remarkable slow light phenomenon can be clearly observed. The maximum of the group delay and group index can reach 528 ps and 2880, respectively. The localization distributions of the electromagnetic field intuitively exhibit the generation and action process of destructive interference. The theoretical investigation of the two-oscillator model further confirms the effectiveness and consistency of the simulation results. In addition, the fourfold symmetric of the proposed PIT HMS supports the liberation from the dependence of incident polarization form. Such an implementation opens a new path for the designing of filtering, switching, and data storing devices.

Section: Structure Design and Numerical Analysismentioning

confidence: 99%

Design of Broadband Plasmon‐Induced Transparency Hybrid Metamaterial Based on the Interaction of the Metal and Dielectric Resonances

Zeng

Zhang

2022

“…The meta-atoms include the top CRFSs , the middle layer four CPRs, and the bottom grid resonator GLM (all with integrated Ge). The GMST also has four gold (conductivity 𝜎 gold = 4.561 ×10 7 S m −1 ) [40] cut wires and four C-shaped dielectric rings to form the PIT, as well as three dielectric spacers. It is noteworthy that the conductivity of the tunable material varies with the modulation of the external stimulus.…”

Section: Gmst Designmentioning

confidence: 99%

Broadband Plasmon‐Induced Transparency to a Electromagnetically Induced Absorption Conversion Metastructure Based on Germanium

Zhu

et al. 2022

A Germanium (Ge) metastructure with switching features from broadband plasmon-induced transparency (PIT) and electromagnetically induced absorption (EIA) is presented, which forms a broadband PIT through the near-field coupling between the localized plasmon resonance and the Mie resonance employing four gold cut wires as bright plasmon resonators and four C-shaped dielectric rings as dark plasmon resonators. A wide transparent window above 0.9 is achieved covering from 0.622 to 0.823 THz with a relative bandwidth of 27.8%. In addition, through phase modulation, a magnetic dipole is generated by the constructive interference of the near-field coupling of the three resonators to realize the PIT to EIA conversion. In addition, a grid-like metastructure is introduced to realize the PIT to EIA conversion by phase modulation. To enhance the EIA bandwidth, another layer of C-shaped reflection plate resonator is introduced to increase the dark mode loss, and a layer of frequency selective surface composed of cross-shaped resonators is also used. Thus under the dual effect, a wide absorption window above 0.75 is achieved covering from 0.647 to 0.756 THz with a relative bandwidth of 15.5%.

“…The integration of the EIT analog and the cross-polarization conversion has been elaborated in ref. [50] but fails to achieve optical delay in the conversion state. The dual-band linear-to-circular polarization conversion (LCPC) induced via the asymmetric EIT responses under both modes has been revealed by Zhu et al [19] with potential in radomes, that is, an expansion of the atomic coherent cancellation [2,3] to the practical information competition of the military despite the low transmittance.…”

Section: Introductionmentioning

confidence: 99%

Circularly Polarized Manipulations with VO₂‐Doped Dielectric Electromagnetically Induced Transparency and Absorption

Sun

Gao

et al. 2022

Superior analogs for electromagnetically induced transparency (EIT) and absorption (EIA) in metasurfaces (MSS) are universal, but fewer integrate both effects in one device, let alone contribute to polarization manipulations. Here, note that asymmetrical EITs are rigorously demonstrated under both polarization incidences in dielectric orthogonal dumbbell‐shaped structures, with a maximum group delay of 335 ps. The transverse magnetic (TM) mode excited EIT holds a transparent window at 1.318 THz close to the transverse electric (TE) mode excited that of 1.358 THz, which triggers the linear‐to‐circular polarization conversion at 1.339 THz with an optimized transmittance of 0.67, validated via the axial ratio. Additionally, asymmetrical EIAs are presented with an embedded metal‐phase VO2 plate, holding a common absorption of 0.51 at 1.340 THz, of which the insulating state affects little to the circular‐polarization output. Given the detuning of two frequencies (1.339 and 1.340 THz) can be compensated by the dispersion properties, it can be understood as the original converted circularly polarized propagating light decays with 0.5‐absorption via phase‐tuned VO2, operating as a temperature‐driven switch. The circular‐polarization transmission and absorption are integrated respectively based on EIT and EIA with the different states of VO2, promising broad prospects in multifunctional devices.