Radiation of a Hertzian dipole immersed in a dissipative medium

Tai, Chen-To; Collin, Robert

doi:10.1109/8.899665

Cited by 58 publications

(55 citation statements)

References 2 publications

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“…A Hertzian dipole radiating in an unbounded lossy medium must be supplied with infinite power, which is not physically meaningful, as shown in [24]. This still applies for a dipole placed in a bounded lossy spherical shell.…”

Section: Appendix B Power Computation Considerationsmentioning

confidence: 99%

“…For instance, radiation efficiencies, specific absorption rate (SAR) and power profiles have been presented in [2], [18], [20] and [17], [21]. Obviously, depending on the source modeling, unrealistically high values of the absolute electric field (therefore SAR) can be obtained [24]. Nevertheless, even for SAR investigation, relative differences and tendencies are still correctly predicted, and this is very useful for the comprehension of the effects of biocompatible insulations.…”

Section: A Human Body Model and Biocompatible Insulation Layermentioning

confidence: 99%

“…The mass density values can be found in [2]. Of course, the use of such ideal sources provides unrealistically high values of the absolute electric field (therefore SAR) [24]. Thus, results are presented in [dB/W] so as better appreciate relative variations.…”

Section: Specific Absorption Ratementioning

confidence: 99%

“…As pointed out in [24], a Hertzian dipole radiating in an unbounded lossy medium must be supplied with infinite power, which is not physically meaningful. To overcome this problem, Tai suggested to insulate the dipole with a lossless sphere.…”

Section: Excitationmentioning

confidence: 99%

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The Effect of Insulating Layers on the Performance of Implanted Antennas

Merli

Fuchs

Mosig

et al. 2011

IEEE Trans. Antennas Propagat.

118

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Abstract-This work presents the analysis of the influence of insulation on implanted antennas for biotelemetry applications in the Medical Device Radiocommunications Service band. Our goal is finding the insulation properties that facilitate power transmission, thus enhancing the communication between the implanted antenna and an external receiver. For this purpose, it has been found that a simplified model of human tissues based on spherical geometries excited by ideal sources (electric dipole, magnetic dipole and Huygens source) provides reasonable accuracy while remaining very tractable due to its analytical formulation. Our results show that a proper choice of the biocompatible internal insulation material can improve the radiation efficiency of the implanted antenna (up to six times for the investigated cases). External insulation facilitates the electromagnetic transition from the biological tissue to the outer free space, reducing the power absorbed by the human body. Summarizing, this work gives insights on the enhancement of power transmission, obtained with the use of both internal, biocompatible and external, flexible insulations. Therefore, it provides useful information for the design of implanted antennas.

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Section: Appendix B Power Computation Considerationsmentioning

confidence: 99%

Section: A Human Body Model and Biocompatible Insulation Layermentioning

confidence: 99%

Section: Specific Absorption Ratementioning

confidence: 99%

Section: Excitationmentioning

confidence: 99%

See 2 more Smart Citations

The Effect of Insulating Layers on the Performance of Implanted Antennas

Merli

Fuchs

Mosig

et al. 2011

IEEE Trans. Antennas Propagat.

118

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“…However, despite providing a nice intuition, this model does not capture the necessary dispersive properties of ZI media (19). Moreover, it also fails to account for the interaction of a small quantum system [e.g., a quantum emitter (QE) such as an atom or a quantum dot] and macroscopic media, because the QE must be insulated from the background macroscopic bodies to produce a consistent result (21,22). However, this preliminary consideration identifies ZI media as a potential candidate to inhibit vacuum fluctuations and spontaneous emission.…”

mentioning

confidence: 99%

Zero-index structures as an alternative platform for quantum optics

Liberal

Engheta

2017

Proc. Natl. Acad. Sci. U.S.A.

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Vacuum fluctuations are one of the most distinctive aspects of quantum optics, being the trigger of multiple nonclassical phenomena. Thus, platforms like resonant cavities and photonic crystals that enable the inhibition and manipulation of vacuum fluctuations have been key to our ability to control light-matter interactions (e.g., the decay of quantum emitters). Here, we theoretically demonstrate that vacuum fluctuations may be naturally inhibited within bodies immersed in epsilon-and-mu-near-zero (EMNZ) media, while they can also be selectively excited via bound eigenmodes. Therefore, zero-index structures are proposed as an alternative platform to manipulate the decay of quantum emitters, possibly leading to the exploration of qualitatively different dynamics. For example, a direct modulation of the vacuum Rabi frequency is obtained by deforming the EMNZ region without detuning a bound eigenmode. Ideas for the possible implementation of these concepts using synthetic implementations based on structural dispersion are also proposed.metamaterial | quantum optics | near-zero refractive index | ENZ | vacuum fluctuation V acuum fluctuations, the fluctuations of a quantized field on its vacuum state around its zero average (1), are considered one of the most distinctive (1-3) and disputed (4) aspects of quantum optics and quantum field theory. Although direct measurements of vacuum fluctuations have only been proposed very recently (5), they are the attributed source of numerous nonclassical phenomena, including, for instance, spontaneous emission (6), Lamb shift (7), Casimir forces (8), molecular energy transfer (9), quantum friction (10), as well as several vacuum amplification effects (3). It is also a well-established fact that macroscopic bodies modify the structure of electromagnetic fields, opening up the possibility of engineering all aforementioned effects (6, 11). For example, because quantum fields fluctuate in a space empty of matter, we could ask what should be the matter filling the space to first inhibit and then selectively engineer vacuum fluctuations (Fig. 1A). Traditional answers to this question have appeared in the form of photonics crystals (PCs) (12-15) and closed cavities (16-18), leading to formidable advances in the ability to control light-matter interactions. In essence, the geometry of periodic structures and resonators can be engineered in such a way so that they do not support eigenmodes on a given frequency range. Here, we demonstrate theoretically that epsilon-mu-near-zero (EMNZ) media (19), also known as matched zero-index (ZI) media (20), that is, a medium with simultaneously zero permittivity and permeability, behaves as a natural inhibitor of vacuum fluctuations. Thus, we propose ZI structures as an alternative platform to manipulate spontaneous emission, and other related effects, possibly leading to the exploration of qualitatively different decay dynamics.Note than one could conceivably approach this problem by using a canonical quantization procedure (1). In this manner, we...

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Computational Study of Dipole Radiation in Re‐Absorbing Perovskite Semiconductors for Optoelectronics

Cho

2021

Advanced Science

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Compared to organic emitters, perovskite materials generally have a small Stokes shift and correspondingly large re‐absorption of dipole emission. Classical optical modelling methods ignoring re‐absorption do not provide an adequate description of the observed light emission properties. Here, optical modelling methods and design rules for perovskite light‐emitting diodes are presented. The transfer‐matrix formalism is used to quantify the Poynting vectors generated by a dipole radiating inside a perovskite optoelectronic device. A strategy is presented to deal with non‐radiative coupling to nearby emissive material that can otherwise lead to non‐physical divergence in the calculation. Stability issues are also investigated regarding coherence of the light propagating in the substrate and the absence of a light absorber in the system. The benefit of the photon recycling effect is taken into account by recursive calculation of the dipole generation profile. The simulation results predict that a high external quantum efficiency of ≈40% is achievable in formamidinium lead triiodide‐based perovskite light‐emitting diodes, by optimization of microcavity, dipole orientation, and photon recycling effects. Contrary to conventional device structures currently reported, this work highlights the benefits of thick charge transport layers and thick perovskite with small Stokes shift.

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Radiation of a Hertzian dipole immersed in a dissipative medium

Cited by 58 publications

References 2 publications

The Effect of Insulating Layers on the Performance of Implanted Antennas

The Effect of Insulating Layers on the Performance of Implanted Antennas

Zero-index structures as an alternative platform for quantum optics

Computational Study of Dipole Radiation in Re‐Absorbing Perovskite Semiconductors for Optoelectronics

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