A broad dual-band switchable graphene-based terahertz metamaterial absorber

Qi, Limei; Liu, Chang; Shah, Syed Mohsin Ali

doi:10.1016/j.carbon.2019.07.011

Cited by 147 publications

(48 citation statements)

References 60 publications

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“…However, the monolayer graphene performs poorly at absorbing light in the visible and near infrared bands, with a mere 2.3% [12][13][14], which limits the quantum efficiency and application in optoelectronic devices. Fortunately, researchers have confirmed that graphene supports surface plasmon resonance (SPR) in the far infrared and terahertz bands [15][16][17][18][19][20][21], enhancing the absorption and broadening the application scope of graphene in optoelectronic and photoelectric devices, such as in modulators, 2 of 13 filters, photoelectric detectors, optical switches, and biosensors [22][23][24][25][26][27][28][29]. Correspondingly, the lack of diversity of graphene-based photoelectric devices in the visible and near-infrared regions has received more urgent attention.…”

Section: Introductionmentioning

confidence: 99%

A Narrow Dual-Band Monolayer Unpatterned Graphene-Based Perfect Absorber with Critical Coupling in the Near Infrared

Chen

et al. 2020

Micromachines

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The combination of critical coupling and coupled mode theory in this study elevated the absorption performance of a graphene-based absorber in the near-infrared band, achieving perfect absorption in the double bands (98.96% and 98.22%), owing to the guided mode resonance (the coupling of the leak mode and guided mode under the condition of phase matching, which revealed 100% transmission or reflection efficiency in the wavelet band), and a third high-efficiency absorption (91.34%) emerged. During the evaluation of the single-structure, cross-circle-shaped absorber via simulation and theoretical analysis, the cross-circle shaped absorber assumed a conspicuous preponderance through exploring the correlation between absorption and tunable parameters (period, geometric measure, and incident angle of the cross-circle absorber), and by briefly analyzing the quality factors and universal applicability. Hence, the cross-circle resonance structure provides novel potential for the design of a dual-band unpatterned graphene perfect absorber in the near-infrared band, and possesses practical application significance in photoelectric detectors, modulators, optical switching, and numerous other photoelectric devices.

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Section: Introductionmentioning

confidence: 99%

A Narrow Dual-Band Monolayer Unpatterned Graphene-Based Perfect Absorber with Critical Coupling in the Near Infrared

Chen

et al. 2020

Micromachines

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“…The thickness of the graphene layer can be set as h_g = 1 nm. Other parameters The permittivity of the graphene can be expressed as [39]:…”

Section: Structural Design and Research Techniquesmentioning

confidence: 99%

Graphene-Assisted Narrow Bandwidth Dual-Band Tunable Terahertz Metamaterial Absorber

Yan

Miao

et al. 2020

Front. Phys.

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A tunable graphene terahertz metamaterial absorber is designed by treating a monolayer continuous dumbbell-shaped structure graphene layer, which can simultaneously realize the narrow bandwidth and dual-band absorption with transverse magnetic (TM) polarization and wide incident angle operation. Two pronounced absorption peaks are caused by the novel toroidal dipole phenomenon and magnetic plasmon polariton. By optimizing the geometry parameters, the relative narrow bandwidths of the two absorption peaks are 26.4 and 23.5 GHz at frequencies of 0.2242 THz and 0.5302 THz, respectively, with the absorption rate above 99.6%. Since the continuous dumbbell-shaped graphene structure is treated in the absorber, a more convenient way to realize the tuning ability by treating a bias voltage compared to the absorbers with discrete graphene structures. The designed device can work at a wide incident angles (up to 80 •) under TM polarization with the absorption above 88% at low frequency. The simulation results are basically in good agreement with the results of the equivalent circuit model. This work offers huge potential applications in terahertz imaging, detecting and sensing, especially in the 6G communication systems.

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“…These can largely improve the practicability of metamaterials in the cloaking, superlens, subwavelength imaging, holography, perfect absorber, sensor, filter, all‐optical modulation, programmable logic operation, nonlinear optics, and so on. [ 40,42–44,54–62 ]…”

Section: Introductionmentioning

confidence: 99%

Tunable Dual‐Split‐Disk Resonator with Electromagnetically Induced Transparency Characteristic

Zheng

Lin

2020

Adv Materials Technologies

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A tunable dual‐split‐disk resonator (TDSDR) composed of top and bottom Au split‐disk resonators (SDRs) in the terahertz (THz) wave is presented. TDSDR exhibits electromagnetically induced transparency (EIT) characteristic by changing the rotation angle of top SDR (θ) and distance between top and bottom SDRs (h). The bright and dark modes are defined by the resonances with θ = 90° and 0°, respectively. The resonances could also be controlled by changing h values. It can generate a tunable sharp resonance by moving the top SDR to change h value. Furthermore, the amplitude of EIT resonance could be tuned and switched on/off state, i.e., bright and dark modes by rotating top SDR with specific h value. When h value is 1 µm, the free spectra range (FSR) could be tuned 0.24 THz and EIT characteristic is not clear. By continuously changing h value to 3 µm, EIT characteristic could be tuned with a modulation depth of 75.58%. The average quality factor (Q‐factor) of resonances is 11.54 and average figure of merit (FOM) is 7.06. When h value is enlarged to 5 µm, EIT characteristic could be tuned with a modulation depth of 62.73%, while the average Q‐factor is 14.50 and average FOM is 9.35.

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A broad dual-band switchable graphene-based terahertz metamaterial absorber

Cited by 147 publications

References 60 publications

A Narrow Dual-Band Monolayer Unpatterned Graphene-Based Perfect Absorber with Critical Coupling in the Near Infrared

A Narrow Dual-Band Monolayer Unpatterned Graphene-Based Perfect Absorber with Critical Coupling in the Near Infrared

Graphene-Assisted Narrow Bandwidth Dual-Band Tunable Terahertz Metamaterial Absorber

Tunable Dual‐Split‐Disk Resonator with Electromagnetically Induced Transparency Characteristic

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