English
Related papers

Related papers: Broadband directional invisibility

200 papers

We explore the phenomenon of unidirectional invisibility in two dimensions, examine its optical realizations, and discuss its three-dimensional generalization. In particular we construct an infinite class of unidirectionally invisible…

Quantum Physics · Physics 2016-07-26 Farhang Loran , Ali Mostafazadeh

A broad class of planar dielectric media with complex permittivity profiles that are fully invisible, for both left and right incidence sides, is introduced. Such optical media are locally isotropic, non-magnetic and belong to the recently…

Optics · Physics 2016-08-24 Stefano Longhi

Achieving exact unidirectional invisibility in a finite frequency band has been an outstanding problem for many years. We offer a simple solution to this problem in two dimensions that is based on our solution to another more basic open…

Quantum Physics · Physics 2019-12-06 Farhang Loran , Ali Mostafazadeh

For the scattering of plane electromagnetic waves by a general possibly anisotropic stationary linear medium in three dimensions, we give a condition on the permittivity and permeability tensors of the medium under which the first Born…

Mathematical Physics · Physics 2024-09-24 Farhang Loran , Ali Mostafazadeh

We outline a method for constructing effectively two-dimensional isotropic optical media that are perfectly and omnidirectionally invisible for both TE and TM waves provided that their wavenumber does not exceed a preassigned value…

Optics · Physics 2018-02-14 Farhang Loran , Ali Mostafazadeh

We develop a transfer-matrix formulation of the scattering of electromagnetic waves by a general isotropic medium which makes use of a notion of electromagnetic transfer matrix $\mathbf{M}$ that does not involve slicing of the scattering…

Quantum Physics · Physics 2020-09-24 Farhang Loran , Ali Mostafazadeh

The phenomenon of half-spectral unidirectional invisibility is introduced for one-dimensional periodic optical structures with tailored real and imaginary refractive index distributions in a non-$\mathcal{PT}$-symmetric configuration. The…

Optics · Physics 2016-01-15 Stefano Longhi

We give explicit criteria for the reflectionlessness, transparency, and invisibility of a finite-range potential in the presence of an incoherent (intensity-dependent) nonlinearity that is confined to the range of the potential. This allows…

Quantum Physics · Physics 2017-10-12 Ali Mostafazadeh , Neslihan Oflaz

We outline a general perturbative method of evaluating scattering features of finite-range complex potentials and use it to examine complex perturbations of a rectangular barrier potential. In optics, these correspond to modulated…

Quantum Physics · Physics 2016-04-18 Ali Mostafazadeh

In a recent work, S.A.R. Horsley and coworkers [Nature Photon 9, 436-439 (2015)] showed rather interestingly that planar dielectric media, for which the real and imaginary parts of the dielectric permittivity are related by spatial…

Optics · Physics 2016-01-26 Stefano Longhi

We show that in one dimension the transfer matrix M of any scattering potential v coincides with the S-matrix of an associated time-dependent non-Hermitian 2 x 2 matrix Hamiltonian H(\tau). If v is real-valued, H(\tau) is pseudo-Hermitian…

Quantum Physics · Physics 2015-06-17 Ali Mostafazadeh

We propose a model for realizing frequency-dependent spatial variations of the probe susceptibility in a cold atomic sample. It is found that the usual Kramers-Kronig (KK) relation between real and imaginary parts of the probe…

Quantum Physics · Physics 2022-03-04 Yan Zhang , Jin-Hui Wu , M. Artoni , G. C. La Rocca

We show that parity-time (PT) symmetric Bragg periodic structures, near the spontaneous PT - symmetry breaking point, can act as unidirectional invisible media. In this regime, the re flection from one end is diminished while it is enhanced…

For a general complex scattering potential defined on a real line, we show that the equations governing invisibility of the potential are invariant under the combined action of parity and time-reversal (PT) transformation. We determine the…

Mathematical Physics · Physics 2013-03-12 Ali Mostafazadeh

Suppression of wave scattering and the realization of transparency effects in engineered optical media and surfaces have attracted great attention in the past recent years. In this work the problem of transparency is considered for optical…

Optics · Physics 2016-05-04 Stefano Longhi

Bragg scattering in sinusoidal PT-symmetric complex crystals of finite thickness is theoretically investigated by the derivation of exact analytical expressions for reflection and transmission coefficients in terms of modified Bessel…

Quantum Physics · Physics 2015-06-03 Stefano Longhi

Nonlinear effects could play a crucial role in addressing optical nonreciprocal behaviors in scattering media. Such behaviors are, however, typically observed within a single transmission channel and predominantly in media with fixed…

Optics · Physics 2025-04-07 Xiao Liu , M. Artoni , G. C. La Rocca , Jin-Hui Wu

We propose a general method to arbitrarily manipulate an electromagnetic wave propagating in a two-dimensional medium, without introducing any scattering. This leads to a whole class of isotropic spatially varying permittivity and…

Electromagnetic invisibility, defined as reflectionless transmission with zero phase delay, imposes strict constraints on metasurface designs that go beyond conventional reflection suppression based on the Kerker effect. This condition can…

Optics · Physics 2026-04-23 Mustafa Yücel , Karim Achouri

A new mechanism of Bragg reflection is identified, one that, remarkably, occurs in a uniform medium and relies on resonant tuning of the medium's parameters. Due to uniformity, reflection ensues over a broad wavelength range, much like a…

Optics · Physics 2023-03-22 Martin W. McCall , Stefanos Fr. Koufidis
‹ Prev 1 2 3 10 Next ›