Compact Broadband Terahertz Perfect Absorber Based on Multi-Interference and Diffraction Effects

Shi, Cheng; Zang, Xiao Fei; Chen, Lin; Peng, Yan; Cai, Bin; Nash, George; Zhu, Yi

doi:10.1109/tthz.2015.2496313

Cited by 58 publications

(15 citation statements)

References 21 publications

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“…In 2009, Landy et al designed an absorber with a modified electrically coupled ring resonator with a cross structure that realized~95% absorption at 1.13 THz [11]. The proposed absorber created new research opportunities in the research of metamaterial absorbers [12][13][14]. These characteristics led to the research boom of the THz absorber [10].…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of an Ultra-Broadband All-Silicon Terahertz Absorber

et al. 2020

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In this article we present and numerically investigate a broadband all-silicon terahertz (THz) absorber which consists of a single-layer periodic array of a diamond metamaterial layer placed on a silicon substrate. We simulated the absorption spectra of the absorber under different structural parameters using the commercial software Lumerical FDTD solutions, and analyzed the absorption mechanism from the distribution of the electromagnetic fields. Finally, the absorption for both transverse electric (TE) and transverse magnetic (TM) polarizations under different incident angles from 0 to 70° were investigated. Herein, electric and magnetic resonances are proposed that result in perfect broadband absorption. When the absorber meets the impedance matching principle in accordance with the loss mechanism, it can achieve a nearly perfect absorption response. The diamond absorber exhibits an absorption of ~100% at 1 THz and achieves an absorption efficiency >90% within a bandwidth of 1.3 THz. In addition, owing to the highly structural symmetry, the absorber has a polarization-independent characteristic. Compared with previous metal–dielectric–metal sandwiched absorbers, the all-silicon metamaterial absorbers can avoid the disadvantages of high ohmic losses, low melting points, and high thermal conductivity of the metal, which ensure a promising future for optical applications, including sensors, modulators, and photoelectric detection devices.

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Section: Introductionmentioning

confidence: 99%

Numerical Study of an Ultra-Broadband All-Silicon Terahertz Absorber

et al. 2020

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“…Design of graphene absorbers with high accuracy is difficult and also very expensive because of its costly laboratory equipment. Hence, multiple interference theorems, and transfer matrix were proposed in [18], [26], [27] to analyze; they are unable to provide a proper guidance on the development of a reliable and accurate graphene absorbers. Numerical methods such as the frequency domain time difference (FDTD), periodic method of moments (PMM), finite element method (FEM) etc., may give excellent precision, however, these techniques are time consuming, and requires high performance computational facilities.…”

Section: Introductionmentioning

confidence: 99%

Cascaded Graphene Frequency Selective Surface Integrated Tunable Broadband Terahertz Metamaterial Absorber

2019

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The quest of novel materials and structures to design an efficient absorber for realizing wave trapping and absorption at terahertz (THz) frequencies is an open topic. But the design of a thin, wideband, and tunable THz absorber is still an arduous job. Hence, in this paper, a hybrid THz metamaterial absorber integrated with a cascaded graphene frequency selective surface (FSS), with ultra-high absorbance over a wide frequency range is designed using an analytical equivalent circuit model. Such an approach provides a feasible way to optimize the device by interrelating the effective electromagnetic and circuit parameters with the unit cell dimensions of FSS. A systematic study and critical analysis over a wide range of device parameters including graphene chemical potential and FSS design variables is demonstrated. A peak dip in reflection coefficient of −30.27 dB is observed at 2.94 THz for an optimal device with a chemical potential (μ c) of 0.38 eV (μ c1), and 0.25 eV (μ c2) in the range of 0.1-4.0 THz. The cascaded FSS configuration results in the unique anti-reflection-based absorption phenomena, which is responsible for the achievement of-10 dB absorption bandwidth of 2.34 THz (0.85-3.19 THz). In addition, the frequencydependent effective permittivity, permeability, and impedance is extracted using reflection data, in order to understand the device physics. Such ultra-thin and broadband absorbing device architecture may confer potential application perspectives in THz sensing, imaging, and detection.

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“…To tackle this problem, doped silicon substrates have been used to create broadband MPAs. Different unit cells patterns, including circular holes [12], rectangular cubes [13,14,15], cross-cave patches [16] sawtooth structures [17], crosses [18,19] and dumbbell shapes [20], have been demonstrated. The broadband absorptions are mainly due to the excitation of plasmonic waveguide modes or by multi-interference and diffraction effects [21].…”

Section: Introductionmentioning

confidence: 99%

An Ultra-Wideband THz/IR Metamaterial Absorber Based on Doped Silicon

et al. 2018

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Metamaterial-based absorbers have been extensively investigated in the terahertz (THz) range with ever increasing performances. In this paper, we propose an all-dielectric THz absorber based on doped silicon. The unit cell consists of a silicon cross resonator with an internal cross-shaped air cavity. Numerical results suggest that the proposed absorber can operate from THz to far-infrared regimes, having an average power absorption of ∼95% between 0.6 and 10 THz. Experimental results using THz time-domain spectroscopy show a good agreement with simulations. The underlying mechanisms for broadband absorption are attributed to the combined effects of multiple cavities modes formed by silicon resonators and bulk absorption in the doped silicon substrate, as confirmed by simulated field patterns and calculated diffraction efficiency. This ultra-wideband absorption is polarization insensitive and can operate across a wide range of the incident angle. The proposed absorber can be readily integrated into silicon-based photonic platforms and used for sensing, imaging, energy harvesting and wireless communications applications in the THz/IR range.

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Compact Broadband Terahertz Perfect Absorber Based on Multi-Interference and Diffraction Effects

Cited by 58 publications

References 21 publications

Numerical Study of an Ultra-Broadband All-Silicon Terahertz Absorber

Numerical Study of an Ultra-Broadband All-Silicon Terahertz Absorber

Cascaded Graphene Frequency Selective Surface Integrated Tunable Broadband Terahertz Metamaterial Absorber

An Ultra-Wideband THz/IR Metamaterial Absorber Based on Doped Silicon

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