Detailed Experiment-Theory Comparison of Mid-Infrared Metasurface Perfect Absorbers

To, Naoki; Juodkazis, Saulius; Nishijima, Yoshiaki

doi:10.3390/mi11040409

Cited by 27 publications

(17 citation statements)

References 33 publications

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“…The surface roughness was not considered in the RCWA calculations in this study. However, previous studies have shown that the effect of surface roughness is significant in plasmonic absorbers [26,27]. Although the present calculations dealt with ideal conditions, our future works can deal with this problem by considering periodic structures that approximate the surface roughness in the RCWA calculations.…”

Section: Methodsmentioning

confidence: 96%

Theoretical and Numerical Analysis of Active Switching for Narrow-Band Thermal Emission with Graphene Ribbon Metasurface

Yada

Shimojo

Okada

et al. 2021

Sensors

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Components smaller than the wavelength of electromagnetic waves are called meta-atoms. Thermal emission can be controlled by an artificial structure in which these meta-atoms are arranged on the surface. This artificial structure is called a metasurface, and its optical properties are determined by the materials and shapes of the meta-atoms. However, optical devices may require active control of thermal emission. In the present study, we theoretically and numerically analyze a wavelength-selective emitter using a graphene ribbon metasurface. The graphene ribbon metasurface consists of a graphene ribbon array, potassium bromide thin film, and silver substrate. The geometric parameters of the graphene metasurface are determined based on an equivalent circuit model that agrees well with the results of the electromagnetic field analysis (rigorous coupled-wave analysis). The proposed emitter causes impedance matching depending on the conductivity of the graphene ribbon in a very narrow wavelength range. The conductivity of graphene can be actively controlled by the gate voltage. Therefore, the proposed emitters may realize near-perfect emission with a high quality factor and active controllable switching for various wavelengths. In addition, the quality factor can be changed by adjusting the electron mobility of graphene. The proposed emitter can be used for optical devices such as thermophotovoltaic systems and biosensing.

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Section: Methodsmentioning

confidence: 96%

Theoretical and Numerical Analysis of Active Switching for Narrow-Band Thermal Emission with Graphene Ribbon Metasurface

Yada

Shimojo

Okada

et al. 2021

Sensors

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“…Additionally, the dephasing time of the inverted ETSC is a critical parameter that can be defined by taking into account the resonance narrowness as follows: Another important factor is V eff which represents the effective mode volume of the confined electromagnetic field in the cavity. Additionally, the effective mode volume is calculated according to V e f f = V ε(r)|E(r)| 2 dV max ε(r)|E(r)| 2 [34][35][36][37][38][39][40][41][42][43][44][45][46], where ε(r) is the dielectric constant, |E(r)| is the electric field strength and V is the volume encompassing the resonator with a boundary in the radiation zone of the cavity mode. As for Figure 11a, the minimum of V eff is 0.02 × 10 5 µm when h 2 = 50 nm.…”

Section: Bar Embedded the Inverted Etsc Configurationmentioning

confidence: 99%

Plasmonic Narrowband Filter Based on an Equilateral Triangular Resonator with a Silver Bar

2021

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A kind of plasmonic structure consisted of an equilateral triangle-shaped cavity (ETSC) and a metal-insulator-metal (MIM) waveguide is proposed to realize triple Fano resonances. Numerically simulated by the finite difference time domain (FDTD) method, Fano resonances inside the structure are also explained by the coupled mode theory (CMT) and standing wave theory. For further research, inverting ETSC could dramatically increase quality factor to enhance resonance wavelength selectivity. After that, a bar is introduced into the ETSC and the inverted ETSC to increase resonance wavelengths through changing the structural parameters of the bar. In addition, working as a highly efficient narrowband filter, this structure owes a good sensitivity (S = 923 nm/RIU) and a pretty high-quality factor (Q = 322) along with a figure of merit (FOM = 710). Additionally, a narrowband peak with 1.25 nm Full-Width-Half-Maximum (FWHM) can be obtained. This structure will be used in highly integrated optical circuits in future.

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“…The wavelength separation between the two resonances (~533 nm) is larger than the 3 dB linewidth of the orthogonal nanoantenna resonance on a glass substrate alone [33,34], which is beneficial for realizing wide-band strong nonlinearity. The interface plays an important role in the real fabrication of metamaterials [35,36], so the effect of interface roughness on linear and nonlinear properties should be considered in practical applications. We compare the transmission spectra of rough and flat AZO interfaces in the coupled structure, and the results are shown in Figure 3c: (1) the main resonance is redshifted, and the weak resonance is blueshifted in the rough interface.…”

Section: Linear Characteristic Analysismentioning

confidence: 99%

Polarization-Independent Large Third-Order-Nonlinearity of Orthogonal Nanoantennas Coupled to an Epsilon-Near-Zero Material

2021

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The nonlinear optical response of common materials is limited by bandwidth and energy consumption, which impedes practical application in all-optical signal processing, light detection, harmonic generation, etc. Additionally, the nonlinear performance is typically sensitive to polarization. To circumvent this constraint, we propose that orthogonal nanoantennas coupled to Al-doped zinc oxide (AZO) epsilon-near-zero (ENZ) material show a broadband (~1000 nm bandwidth) large optical nonlinearity simultaneously for two orthogonal polarization states. The absolute maximum value of the nonlinear refractive index n2 is 7.65 cm2∙GW−1, which is 4 orders of magnitude larger than that of the bare AZO film and 7 orders of magnitude larger than that of silica. The coupled structure not only realizes polarization independence and strong nonlinearity, but also allows the sign of the nonlinear response to be flexibly tailored. It provides a promising platform for the realization of ultracompact, low-power, and highly nonlinear all-optical devices on the nanoscale.

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Detailed Experiment-Theory Comparison of Mid-Infrared Metasurface Perfect Absorbers

Cited by 27 publications

References 33 publications

Theoretical and Numerical Analysis of Active Switching for Narrow-Band Thermal Emission with Graphene Ribbon Metasurface

Theoretical and Numerical Analysis of Active Switching for Narrow-Band Thermal Emission with Graphene Ribbon Metasurface

Plasmonic Narrowband Filter Based on an Equilateral Triangular Resonator with a Silver Bar

Polarization-Independent Large Third-Order-Nonlinearity of Orthogonal Nanoantennas Coupled to an Epsilon-Near-Zero Material

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