Metamaterials and Transformation Optics

Luan, Pi Gang

doi:10.1007/978-94-017-9392-6_2

Cited by 4 publications

(2 citation statements)

References 62 publications

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“…It is worth mentioning that not all types of metamaterials exhibit a negative refractive index. A necessary condition for achieving a negative refractive index is that both permittivity and permeability have negative values [24,25]. However, some metamaterials, such as ENG and mu-negative (MNG), can also display a negative refractive index in certain frequency domains.…”

Section: Introductionmentioning

confidence: 99%

Controlling Thermal Radiation in Photonic Quasicrystals Containing Epsilon-Negative Metamaterials

Mikaeeli,

Keshavarz,

Baseri

et al. 2023

Applied Sciences

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The transfer matrix approach is used to study the optical characteristics of thermal radiation in a one-dimensional photonic crystal (1DPC) with metamaterial. In this method, every layer within the multilayer structure is associated with its specific transfer matrix. Subsequently, it links the incident beam to the next layer from the previous layer. The proposed structure is composed of three types of materials, namely InSb, ZrO2, and Teflon, and one type of epsilon-negative (ENG) metamaterial and is organized in accordance with the laws of sequencing. The semiconductor InSb has the capability to adjust bandgaps by utilizing its thermally responsive permittivity, allowing for tunability with temperature changes, while the metamaterial modifies the bandgaps according to its negative permittivity. Using quasi-periodic shows that, in contrast to employing absolute periodic arrangements, it produces more diverse results in modifying the structure’s band-gaps. Using a new sequence arrangement mixed-quasi-periodic (MQP) structure, which is a combination of two quasi periodic structures, provides more freedom of action for modifying the properties of the medium than periodic arrangements do. The ability to control thermal radiation is crucial in a range of optical applications since it is frequently unpolarized and incoherent in both space and time. These configurations allow for the suppression and emission of thermal radiation in a certain frequency range due to their fundamental nature as photonic band-gaps (PBGs). So, we are able to control the thermal radiation by changing the structure arrangement. Here, the We use an indirect method based on the second Kirchoff law for thermal radiation to investigate the emittance of black bodies based on a well-known transfer matrix technique. We can measure the transmission and reflection coefficients with associated transmittance and reflectance, T and R, respectively. Here, the effects of several parameters, including the input beam’s angle, polarization, and period on tailoring the thermal radiation spectrum of the proposed structure, are studied. The results show that in some frequency bands, thermal radiation exceeded the black body limit. There were also good results in terms of complete stop bands for both TE and TM polarization at different incident angles and frequencies. This study produces encouraging results for the creation of Terahertz (THz) filters and selective thermal emitters. The tunability of our media is a crucial factor that influences the efficiency and function of our desired photonic outcome. Therefore, exploiting MQP sequences or arrangements is a promising strategy, as it allows us to rearrange our media more flexibly than quasi-periodic sequences and thus achieve our optimal result.

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Section: Introductionmentioning

confidence: 99%

Controlling Thermal Radiation in Photonic Quasicrystals Containing Epsilon-Negative Metamaterials

Mikaeeli,

Keshavarz,

Baseri

et al. 2023

Applied Sciences

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“…Metamaterials usually refer to artificially engineered structures for realizing various unusual optical/electromagnetic properties such as negative refraction [1,2], subwavelength imaging [3], indefinite permittivity [4], near-perfect absorption [5], or invisibility [6,7]. These unusual properties are mainly achieved through the resonance, conductivity, and directionality of the structural components such as split-ring resonators (SRRs), metallic rods array, or subwavelength dielectric-metal multilayers [8]. The resonance and directionality of the constituent components imply that the metamaterials are inherently dispersive, absorptive, and anisotropic.…”

Section: Introductionmentioning

confidence: 99%

Effective Electrodynamics Theory for the Hyperbolic Metamaterial Consisting of Metal–Dielectric Layers

Luan

2020

Crystals

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In this work, we study the dynamical behaviors of the electromagnetic fields and material responses in the hyperbolic metamaterial consisting of periodically arranged metallic and dielectric layers. The thickness of each unit cell is assumed to be much smaller than the wavelength of the electromagnetic waves, so the effective medium concept can be applied. When electromagnetic (EM) fields are present, the responses of the medium in the directions parallel to and perpendicular to the layers are similar to those of Drude and Lorentz media, respectively. We derive the time-dependent energy density of the EM fields and the power loss in the effective medium based on Poynting theorem and the dynamical equations of the polarization field. The time-averaged energy density for harmonic fields was obtained by averaging the energy density in one period, and it reduces to the standard result for the lossless dispersive medium when we turn off the loss. A numerical example is given to reveal the general characteristics of the direction-dependent energy storage capacity of the medium. We also show that the Lagrangian density of the system can be constructed. The Euler–Lagrange equations yield the correct dynamical equations of the electromagnetic fields and the polarization field in the medium. The canonical momentum conjugates to every dynamical field can be derived from the Lagrangian density via differentiation or variation with respect to that field. We apply Legendre transformation to this system and find that the resultant Hamiltonian density is identical to the energy density up to an irrelevant divergence term. This coincidence implies the correctness of the energy density formula we obtained before. We also give a brief discussion about the Hamiltonian dynamics description of the system. The Lagrangian description and Hamiltonian formulation presented in this paper can be further developed for studying the elementary excitations or quasiparticles in other hyperbolic metamaterials.

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Electrostatic Waves in Photonic Hypercrystals

Moradi

2023

Springer Series in Optical Sciences

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Metamaterials and Transformation Optics

Cited by 4 publications

References 62 publications

Controlling Thermal Radiation in Photonic Quasicrystals Containing Epsilon-Negative Metamaterials

Controlling Thermal Radiation in Photonic Quasicrystals Containing Epsilon-Negative Metamaterials

Effective Electrodynamics Theory for the Hyperbolic Metamaterial Consisting of Metal–Dielectric Layers

Electrostatic Waves in Photonic Hypercrystals

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