Electrical access to critical coupling of circularly polarized waves in graphene chiral metamaterials

Kim, Teun-Teun; Oh, Suhk Kun; Kim, Hyeon‐Don; Park, Hyun Sung; Hess, Ortwin; Min, Bumki; Zhang, Shuang

doi:10.1126/sciadv.1701377

Cited by 131 publications

(95 citation statements)

References 49 publications

(55 reference statements)

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“…Due to the uncoupled nature of resonances for left-handed and right-handed circularly-polarized light, this method can be applied independently to left-handed and right-handed circular polarization. Using this formalism, the contribution of each mode of resonator into the complex transmission T is the following 55 : where ν n denotes the resonant frequencies of the metasurface, Γ r n and Γ i n are the radiation and intrinsic losses of the resonances respectively, and ϕ n represents the phase delay due to the thickness of the metasurface for each resonance mode. In our case, the transmission for RCP and LCP waves can be perfectly described by the system with four resonant frequencies (N = 4).…”

Section: Resultsmentioning

confidence: 99%

Optically tunable terahertz chiral metasurface based on multi-layered graphene

Masyukov

Vozianova

Grebenchukov

et al. 2020

Sci Rep

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Active manipulation of the polarization states at terahertz frequencies is crucially helpful for polarization-sensitive spectroscopy, having significant applications such as non-contact Hall measurements, vibrational circular dichroism measurements and anisotropy imaging. the weakness of polarization manipulation provided by natural materials can be overcomed by chiral metamaterials. Chiral metamaterials have a huge potential to achieve the necessary polarization effects, hence they provide the basis for applications such as ultracompact polarization components. terahertz chiral metamaterials that allow dynamic polarization modulation of terahertz waves are of great practical interest and still challenging. Here, we show that terahertz metasurface based on the four conjugated "petal" resonators integrated with multi-layered graphene (MLG) can enable dynamically tunable chiroptical response using optical pumping. In particular, a change of ellipticity angle of 20° is observed around 0.76 THz under optical pumping by a 980 nm continuous wave (CW) laser. Furthermore, using temporal coupled-mode theory, our study also reveals that the chiroptical response of the proposed multi-layered graphene-based metasurface is strongly dependent on the influence of optical pumping on the loss parameters of resonance modes, leading to actively controllable polarization states of the transmitted terahertz waves. the present work paves the way for the realization of fundamental terahertz components capable for active polarization manipulation.

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Section: Resultsmentioning

confidence: 99%

Optically tunable terahertz chiral metasurface based on multi-layered graphene

Masyukov

Vozianova

Grebenchukov

et al. 2020

Sci Rep

View full text Add to dashboard Cite

show abstract

“…6(b). Recently, many graphene-meta-hybridized tunable metadevices were demonstrated in both the THz [120][121][122][123][124] and IR regimes [125][126][127][128][129][130][131], which exhibit diversified functionalities, such as tunable absorbers [120,123,130], phase modulators [128,129], active polarization controllers [124], and beam steering [131]. Unfortunately, the phase tuning ranges of these graphene-metasurfaces are all very limited.…”

Section: 4a Electrically Tunable Metasurfacesmentioning

confidence: 99%

Electromagnetic metasurfaces: physics and applications

et al. 2019

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H-shaped resonators (inset) are adopted to realize, respectively, the desired B layer with negative ε and A layers with positive ε at the working frequencies [25]. (d) Top and middle panels: interference model and practical design of the metamaterial antireflection coating. Middle panel: experimentally measured reflectance and transmittance spectra for the normal incidence case. The solid and dashed lines represent the reflectance and transmittance of a bare GaAs surface [26]. (a) Figure 1 reprinted with permission from Martín-Moreno et al.,

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“…Since chirality is inherently a three-dimensional (3D) phenomenon that requires coupling between the local electric and the magnetic dipoles [16,17], artificial constituents are usually designed with complex conformations [18], such as spiral with multiple helices [11,16,19], or near-field coupled multilayer metamaterials [20,21]. Polarity reversal of intrinsic chirality is usually accompanied by 3D structural reconfiguration of metamaterial constituents via various approaches [22][23][24], such as by integrating semiconductors (silicon) [18], phase change materials (Ge 2 Sb 2 Te 5 ) [25], graphene [26], magnesium [24], DNA scaffold [27], and MEMS actuators [11,19]. However, a structural reconfiguration usually demands intense stimuli, like large dosage of optical pump fluence (∼1 mJ/cm 2 ) [18], high voltage (∼350 V) [19], high temperature (180 ∘ C) [25], chemical reaction (hydrogenation) [24], or pneumatic control (10 Pa) [11] that limits the applications of these fascinating devices.…”

Section: Introductionmentioning

confidence: 99%

Electrically Programmable Terahertz Diatomic Metamolecules for Chiral Optical Control

et al. 2019

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Optical chirality is central to many industrial photonic technologies including enantiomer identification, ellipsometry-based tomography, and spin multiplexing in optical communications. However, a substantial chiral response requires a three-dimensional constituent, thereby making the morphology highly complex to realize structural reconfiguration. Moreover, an active reconfiguration demands intense dosage of external stimuli that pose a major limitation for on-chip integration. Here, we report a low bias, electrically programmable synthetic chiral paradigm with a remarkable reconfiguration among levorotatory, dextrorotatory, achiral, and racemic conformations. The switchable optical activity induced by the chiral conformations enables a transmission-type duplex spatial light modulator for terahertz single pixel imaging. The prototype delivers a new strategy towards reconfigurable stereoselective photonic applications and opens up avenues for on-chip programmable chiral devices with tremendous applications in biology, medicine, chemistry, and photonics.

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Electrical access to critical coupling of circularly polarized waves in graphene chiral metamaterials

Abstract: Electric control of coupling in hybrid graphene/metamaterial system enables strong selective modulation of light polarization.

Cited by 131 publications

References 49 publications

Optically tunable terahertz chiral metasurface based on multi-layered graphene

Optically tunable terahertz chiral metasurface based on multi-layered graphene

Electromagnetic metasurfaces: physics and applications

Electrically Programmable Terahertz Diatomic Metamolecules for Chiral Optical Control

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