English
Related papers

Related papers: Superluminal pulse reflection from a weakly absorb…

200 papers

The slow light effects of an amplitude modulated Gaussian (AMG) pulse in a cesium atomic vapor are presented. In a single-$\Lambda$ type electromagnetically induced transparency (EIT) medium, more severe distortion is observed for an AMG…

Quantum Physics · Physics 2009-01-21 Wenzhuo Tang , Bin Luo , Yu Liu , Hong Guo

We consider pulse propagation in a linear anomalously dispersive medium where the group velocity exceeds the speed of light in vacuum (c) or even becomes negative. A signal velocity is defined operationally based on the optical…

Optics · Physics 2009-11-07 A. Kuzmich , A. Dogariu , L. J. Wang , P. W. Milonni , R. Y. Chiao

We show theoretically the presence of electromagnetically induced transparency (EIT) like feature in a {\Lambda}-type atom-molecule coupled system. We demonstrate that EIT in such a systems has a sharp dispersion characteristic which is…

Optics · Physics 2022-11-23 Sandeep Sharma , Bimalendu Deb , Tarak N. Dey

We theoretically propose that Weyl semimetals may exhibit negative refraction at some frequencies close to the plasmon frequency, allowing transverse magnetic (TM) electromagnetic waves with frequencies smaller than the plasmon frequency to…

Optics · Physics 2017-09-11 M. Shoufie Ukhtary , Ahmad R. T. Nugraha , Riichiro Saito

The extraordinary properties of laser-induced transparency of a negative-index slab and parametric amplification for a backward-wave signal are investigated. The effects of the idler absorption and phase mismatch on the amplification of the…

The effect of ultrashort laser-induced morphological changes upon irradiation of silicon with double pulse sequences is investigated under conditions that lead to mass removal. The temporal delay between twelve double and equal-energy…

Materials Science · Physics 2013-09-04 M. Barberoglou , G. D. Tsibidis , D. Gray , E. Magoulakis , C. Fotakis , E. Stratakis , P. A. Loukakos

We study the time-resolved reflectivity spectrum of a switched planar GaAs-AlAs microcavity. Between 5 and 40 ps after the switching (pump) pulse we observe a strong excess probe reflectivity and a change of the frequency of light trapped…

Refraction at the interface between two materials is fundamental to the interaction of light with photonic devices and to the propagation of light through the atmosphere at large. Underpinning the traditional rules for the refraction of an…

Optics · Physics 2021-02-02 Basanta Bhaduri , Murat Yessenov , Ayman F. Abouraddy

If the gravitational lens is surrounded by non-homoheneous plasma, in addition to the vacuum gravitational deflection, chromatic refraction occurs. Also, the speed of signal propagation decreases compared to vacuum. In this article, we…

General Relativity and Quantum Cosmology · Physics 2023-07-12 Gennady S. Bisnovatyi-Kogan , Oleg Yu. Tsupko

It is shown theoretically that an optical bottle resonator with a nanoscale radius variation can perform a multi-nanosecond long dispersionless delay of light in a nanometer-order bandwidth with minimal losses. Experimentally, a 3 mm long…

Optics · Physics 2015-06-16 M. Sumetsky

The propagation of a weak probe field in a four-level N-type quantum system in the presence of spontaneously generated coherence (SGC) is theoretically investigated. The optical properties of the system are studied and it is shown that the…

Atomic and Molecular Clusters · Physics 2013-03-05 Lida Ebrahimi Zohravi , Majid Abedi , Mohammad Mahmoudi

A novel deflection effect of an intense laser beam with spin angular momentum is revealed theoretically by an analytical modeling using radiation pressure and momentum balance of laser plasma interaction in the relativistic regime, as a…

Plasma Physics · Physics 2019-12-16 Y. H. Tang , Z. Gong , J. Q. Yu , Y. R. Shou , X. Q. Yan

Composite dark matter (DM) comprised of electrically charged constituents can interact with the electromagnetic field via the particle's dipole moment. This interaction results in a dispersive optical index of refraction for the DM medium.…

High Energy Physics - Phenomenology · Physics 2016-07-18 Audrey K. Kvam , David C. Latimer

Large light deflection angles are produced in the strong gravitational field regions around neutron stars and black holes. In the case of binary systems, part of the photons emitted from the companion star towards the collapsed object are…

Astrophysics · Physics 2015-06-24 S. Campana , A. Parodi , L. Stella

The optical absorption of nanoscale thickness semiconductor films on top of light-trapping structures based on optical interference effects combined with spectrum-splitting structures is theoretically investigated. Nearly perfect absorption…

Optics · Physics 2015-06-23 Jiang-Tao Liu , Xin-Hua Deng , Wen Yang , Jun Li

The concept of phase and dwell times used in tunneling is extended to quantum collisions to derive a relation between the phase and dwell time delays in scattering. This relation can be used to remove the near threshold s-wave singularities…

Quantum Physics · Physics 2008-11-26 Neelima G. Kelkar

The quantum dynamics of a system of Rb atoms, modeled by a V-type three-level system interacting with intense probe and pump pulses, are studied. The time-delay-dependent transient-absorption spectrum of an intense probe pulse is thus…

Atomic Physics · Physics 2018-02-14 Vadim Becquet , Stefano M. Cavaletto

This paper reports the observation of ultra-superluminal pulse propagation in GaAs/AlGaAs multiple contact heterostuctures in a superradiant emission regime, and shows definitively that it is a different class of emission from conventional…

Strongly Correlated Electrons · Physics 2015-08-25 Peter P. Vasil'ev , Richard V. Penty , Ian H. White

We develop a perturbative theory that describes a superluminal refractive perturbation propagating in a dispersive medium and the subsequent excitation of the quantum vacuum zero-point fluctuations. We find a process similar to the…

In solid-state dark matter detectors, energy accumulation due to ionizing radiation should produce delayed low-energy background similar to the background produced by energy deposited by mechanical stress. The tunneling two-level systems…

Instrumentation and Detectors · Physics 2022-10-11 Sergey Pereverzev
‹ Prev 1 8 9 10 Next ›