scholarly journals Giant field enhancement in longitudinal epsilon-near-zero films

2017 ◽  
Vol 95 (16) ◽  
Author(s):  
Mohammad Kamandi ◽  
Caner Guclu ◽  
Ting Shan Luk ◽  
George T. Wang ◽  
Filippo Capolino
Keyword(s):  
Field Enhancement ◽  
Epsilon Near Zero

scholarly journals Quantum plasmonic epsilon near zero: field enhancement and cloaking

2018 ◽  
Vol 26 (12) ◽  
pp. 15656 ◽  
Author(s):  
Ali Khademi ◽  
Timothy Dewolf ◽  
Reuven Gordon
Keyword(s):  
Field Enhancement ◽  
Zero Field ◽  
Epsilon Near Zero

scholarly journals Modeling and observation of mid-infrared nonlocality in effective epsilon-near-zero ultranarrow coaxial apertures

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Daehan Yoo ◽  
Ferran Vidal-Codina ◽  
Cristian Ciracì ◽  
Ngoc-Cuong Nguyen ◽  
David R. Smith ◽  
...  
Keyword(s):  
Field Enhancement ◽  
Atomic Layer ◽  
Atomic Scale ◽  
Large Area ◽  
Infrared Sensors ◽  
Mid Infrared ◽  
Critical Gap ◽  
Nanophotonic Devices ◽  
Extreme Scale ◽  
Epsilon Near Zero

Abstract With advances in nanofabrication techniques, extreme-scale nanophotonic devices with critical gap dimensions of just 1–2 nm have been realized. Plasmons in such ultranarrow gaps can exhibit nonlocal response, which was previously shown to limit the field enhancement and cause optical properties to deviate from the local description. Using atomic layer lithography, we create mid-infrared-resonant coaxial apertures with gap sizes as small as 1 nm and observe strong evidence of nonlocality, including spectral shifts and boosted transmittance of the cutoff epsilon-near-zero mode. Experiments are supported by full-wave 3-D nonlocal simulations performed with the hybridizable discontinuous Galerkin method. This numerical method captures atomic-scale variations of the electromagnetic fields while efficiently handling extreme-scale size mismatch. Combining atomic-layer-based fabrication techniques with fast and accurate numerical simulations provides practical routes to design and fabricate highly-efficient large-area mid-infrared sensors, antennas, and metasurfaces.

scholarly journals Defect-Induced Tunable Permittivity of Epsilon-Near-Zero in Indium Tin Oxide Thin Films

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 922 ◽  
Author(s):  
Jiqing Lian ◽  
Dawei Zhang ◽  
Ruijin Hong ◽  
Peizhen Qiu ◽  
Taiguo Lv ◽  
...  
Keyword(s):  
Thin Films ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Plasma Oscillation ◽  
Field Enhancement ◽  
Fdtd Simulation ◽  
Structural Defects ◽  
Defect States ◽  
Vacancy Defects ◽  
Epsilon Near Zero

Defect-induced tunable permittivity of Epsilon-Near-Zero (ENZ) in indium tin oxide (ITO) thin films via annealing at different temperatures with mixed gases (98% Ar, 2% O2) was reported. Red-shift of λENZ (Epsilon-Near-Zero wavelength) from 1422 nm to 1995 nm in wavelength was observed. The modulation of permittivity is dominated by the transformation of plasma oscillation frequency and carrier concentration depending on Drude model, which was produced by the formation of structural defects and the reduction of oxygen vacancy defects during annealing. The evolution of defects can be inferred by means of X-ray diffraction (XRD), atomic force microscopy (AFM), and Raman spectroscopy. The optical bandgaps (Eg) were investigated to explain the existence of defect states. And the formation of structure defects and the electric field enhancement were further verified by finite-difference time domain (FDTD) simulation.

scholarly journals Magnetic field concentration assisted by epsilon-near-zero media

2017 ◽  
Vol 375 (2090) ◽  
pp. 20160059 ◽  
Author(s):  
Iñigo Liberal ◽  
Yue Li ◽  
Nader Engheta
Keyword(s):  
Magnetic Field ◽  
Enhancement Factor ◽  
Light Emission ◽  
Field Enhancement ◽  
Intrinsic Property ◽  
Inhomogeneous Magnetic Field ◽  
Additional Information ◽  
Magnetic Field Enhancement ◽  
The Magnetic Field ◽  
Epsilon Near Zero

Strengthening the magnetic response of matter at optical frequencies is of fundamental interest, as it provides additional information in spectroscopy, as well as alternative mechanisms to manipulate light at the nanoscale. Here, we demonstrate theoretically that epsilon-near-zero (ENZ) media can enhance the magnetic field concentration capabilities of dielectric resonators. We demonstrate that the magnetic field enhancement factor is unbounded in theory, and it diverges as the size of the ENZ host increases. In practice, the maximal enhancement factor is limited by dissipation losses in the host, and it is found via numerical simulations that ENZ hosts with moderate losses can enhance the performance of a circular dielectric rod resonator by around one order of magnitude. The physical mechanism behind this process is the strongly inhomogeneous magnetic field distributions induced by ENZ media in neighbouring dielectrics. We show that this is an intrinsic property of ENZ media, and that the occurrence of resonant enhancement is independent of the shape of the host. These results might find applications in spectroscopy, in sensing, in light emission and, in general, in investigating light–matter interactions beyond electric dipole transitions. This article is part of the themed issue ‘New horizons for nanophotonics’.

scholarly journals Dynamically controlling local field enhancement at an epsilon-near-zero/dielectric interface via nonlinearities of an epsilon-near-zero medium

Nanophotonics ◽  
2020 ◽  
Vol 9 (16) ◽  
pp. 4831-4837
Author(s):  
Alexander Baev ◽  
Paras N. Prasad ◽  
M. Zahirul Alam ◽  
Robert W. Boyd
Keyword(s):  
Local Field ◽  
Enhancement Factor ◽  
Polarized Light ◽  
Field Enhancement ◽  
Field Enhancement Factor ◽  
Local Fields ◽  
Great Promise ◽  
Matrix Formalism ◽  
Local Field Enhancement ◽  
Epsilon Near Zero

AbstractFor p-polarized light incident on an interface between an ordinary dielectric and an epsilon-near-zero (ENZ) material, an enhancement of the component of the electric field, normal to this interface, has been shown to occur. This local field enhancement holds great promise for amplifying nonlinear optical processes and for other applications requiring ultrastrong local fields in epsilon-near-zero based technologies. However, the loss associated with the imaginary part of the dielectric constant of an epsilon-near-zero material can greatly suppress the field enhancement factor. In this study, we analyze, using density matrix formalism, the field enhancement factor for a saturable two-level system that exhibits second- and third-order nonlinearities. We show that, in such a system, an almost lossless ENZ response can arise as a consequence of saturable nonlinearity and that the local field enhancement factor can be readily controlled dynamically by adjusting the intensity of the incident electromagnetic wave. Our findings provide for the first time a pathway to design a material exhibiting an external field responsive epsilon-near-zero behavior for applications in nonlinear photonics.

scholarly journals Effect of longitudinal epsilon-near-zero regime in dynamics of ultrashort laser pulses in hyperbolic metamaterials

2021 ◽  
Vol 2015 (1) ◽  
pp. 012098
Author(s):  
Vladimir Novikov
Keyword(s):  
Pulse Propagation ◽  
Field Enhancement ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Pulse Delay ◽  
Hyperbolic Metamaterials ◽  
Spectral Point ◽  
Slow Pulse ◽  
Ultrashort Laser ◽  
Epsilon Near Zero

Abstract Optical properties of hyperbolic metamaterials (HMMs) are in stark contrast to properties of ordinary media that fuels interest to various applications of HMMs in photonics. Special attention is attributed to the epsilon-near zero regime (ENZ) of HMMs that is the spectral point in which real part of the permittivity of the HMM becomes zero. This is accompanied by the effects of field enhancement having far-reaching applications. Here we focus on the experimental and theoretical investigation of the propagation of an ultrashort laser pulse through the silver nanorod-based HMM slab in the spectral range over the ENZ. We revealed pronounced resonant change of the pulse delay in HMMs and the transition between the superluminal and slow pulse propagation at the ENZ spectral point. Observed dynamical phenomena are confirmed theoretically and attributed to unusual case when the spectral half of an ultrashort pulse has elliptical dispersion and another has the hyperbolic one. Special attention is payed to the propagation of chirped laser pulses in the HMMs.

scholarly journals Extreme local field enhancement by hybrid epsilon-near-zero–plasmon mode in thin films of transparent conductive oxides

2020 ◽  
Vol 45 (20) ◽  
pp. 5744
Author(s):  
Innem V. A. K. Reddy ◽  
Josep M. Jornet ◽  
Alexander Baev ◽  
Paras N. Prasad
Keyword(s):  
Thin Films ◽  
Local Field ◽  
Field Enhancement ◽  
Plasmon Mode ◽  
Transparent Conductive Oxides ◽  
Local Field Enhancement ◽  
Epsilon Near Zero

scholarly journals Atomic Layer Engineering of Epsilon‐Near‐Zero Ultrathin Films with Controllable Field Enhancement

2020 ◽  
Vol 7 (17) ◽  
pp. 2000844
Author(s):  
Sudip Gurung ◽  
Aleksei Anopchenko ◽  
Subhajit Bej ◽  
Jay Joyner ◽  
Jason D. Myers ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Field Enhancement ◽  
Atomic Layer ◽  
Epsilon Near Zero

Field Enhancement of Epsilon-Near-Zero Modes in Atomic-Layer-Deposited ZnO:Al Nanolayers

2019 ◽  
Author(s):  
Aleksei Anopchenko ◽  
Sudip Gurung ◽  
Subhajit Bej ◽  
Jay Joyner ◽  
Ho Wai Howard Lee
Keyword(s):  
Field Enhancement ◽  
Atomic Layer ◽  
Zero Modes ◽  
Epsilon Near Zero
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