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Related papers: Pulsed light beams in vacuum with superluminal and…

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Broadband, coherent light carrying optical angular momentum is of potential utility for a variety of classical and quantum communication applications, but at present few such sources exist. We study the generation of supercontinua in a ring…

Optics · Physics 2020-01-08 Calum Maitland , Fabio Biancalana

Almost twenty years ago the light was slowed down to less than $10^{-7}$ of its vacuum speed in a cloud of ultracold atoms of sodium. Upon a sudden turn-off of the coupling laser, a slow light pulse can be imprinted on cold atoms such that…

Optics · Physics 2018-01-10 Tamar Goldzak , Alexei A. Mailybaev , Nimrod Moiseyev

A large distance propagation in turbulent atmosphere results in disintegration of laser beam into speckles. We find that the most intense speckle approximately preserves both the Gaussian shape and the diameter of the initial collimated…

Optics · Physics 2019-12-10 Pavel M. Lushnikov , Natalia Vladimirova

Although the group delay of classical pulses through a barrier may suggest superluminality, the information transfer is limited by the precursor which propagates at the vacuum light speed. Single photons, however, have infinite tails, and…

Quantum Physics · Physics 2024-09-24 Jan Gulla , Johannes Skaar

The phase velocity of light is co-parallel to the direction of energy flow in classical vacuum. However, in certain uncommon materials, these two vectors can be oppositely directed, in which case the phase velocity is termed `negative'.…

Optics · Physics 2007-05-23 Tom G. Mackay , Akhlesh Lakhtakia

We report the experimental observation of a three-dimensional abruptly autofocusing effect by synthesizing a radially distributed Airy beam with two counter-propagating Airy pulses in time. As the wave packet propagates in a dispersive…

Optics · Physics 2025-04-08 Youngbin Park , Xiaolin Su , Qian Cao , Andy Chong

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

Providing efficient nonlinear optical frequency conversion is essential for numerous applications. Fundamentally, dispersion limits the efficiency of such processes through mismatch of the phase velocities and the group velocities of the…

Optics · Physics 2020-07-27 Georgiy Shoulga , Alon Bahabad

It has been found in several papers that, because of quantum corrections, light front can propagate with superluminal velocity in gravitational fields and even in flat space-time across two conducting plates. We show that, if this is the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 A. D. Dolgov , I. D. Novikov

Light from `point sources' such as supernovae is observed with a beam width of order of the sources' size - typically less than 1 AU. Such a beam probes matter and curvature distributions that are very different from coarse-grained…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Chris Clarkson , George Ellis , Andreas Faltenbacher , Roy Maartens , Obinna Umeh , Jean-Philippe Uzan

Slow light of an amplitude modulated Gaussian (AMG) pulse in cesium vapor is demonstrated and studied, as an appropriate amplitude modulation to a single pulse can expand its spectrum and thus increase the utilization efficiency of the…

Quantum Physics · Physics 2015-05-13 Wenzhuo Tang , Bin Luo , Yu Liu , Hong Guo

We present a detailed analysis of the recently demonstrated technique to generate quasi-stationary pulses of light [M. Bajcsy {\it et al.}, Nature (London) \textbf{426}, 638 (2003)] based on electromagnetically induced transparency. We show…

Quantum Physics · Physics 2016-08-16 F. E. Zimmer , A. André , M. D. Lukin , M. Fleischhauer

We develop models for the propagation of intense pulses in solid state media which can have either saturated absorption or exhibit reverse absorption . We show that the experiments of Bigelow {\it et al.}[Phys. Rev. Lett. {\bf 90}, 113903…

Quantum Physics · Physics 2007-05-23 G. S. Agarwal , T. N. Dey

The dynamics of several light filaments (spatial optical solitons) propagating in an optically nonlinear and non-local random medium is investigated using the paradigms of the physics of complexity. Cluster formation is interpreted as a…

Optics · Physics 2007-05-23 Claudio Conti

We investigate lensing and waveguiding properties of an atomic Bose-Einstein condensate for ultraslow pulse generated by electromagnetically induced transparency method. We show that a significant time delay can be controllably introduced…

Optics · Physics 2011-03-25 Devrim Tarhan , Alphan Sennaroglu , Ozgur E. Mustecaplioglu

We investigate the behavior of the light pulse in $Lambda$-type cold atomic gases with two counterpropagating control lights with equal strength by directly simulating the dynamic equations and exploring the dispersion relation. Our…

Quantum Physics · Physics 2010-04-28 Ran Wei , Bo Zhao , Youjin Deng , Shuai Chen , Zeng-Bing Chen , Jian-Wei Pan

We analyse a system in which, due to entanglement between the spin and spatial degrees of freedom, the reduced transmitted state has the shape of the freely propagating pulse translated in the complex co-ordinate plane. In the case an…

Quantum Physics · Physics 2015-05-14 D. Sokolovski , R. Sala Mayato

A comparative analysis of two approaches to description of the light modulation pulse delay in a saturable absorber is presented. According to the simplest model, the delay of the optical pulse is a result of distortion of its shape due to…

Optics · Physics 2015-05-27 V. S. Zapasskii , G. G. Kozlov

Recent suggestions for a modification of general relativity to provide an alternative approach to gravity in connection with the dark energy (matter) problem imply a long range vector component of the gravitational field. This could lead to…

Astrophysics · Physics 2008-03-14 C. Sivaram

We consider light propagation above the light line in arrays of spherical dielectric nanoparticles. It is demonstrated numerically that quasi-bound leaky modes of the array can propagate both stationary waves and light pulses to a distance…

Optics · Physics 2016-08-24 Evgeny N. Bulgakov , Dmitrii N. Maksimov
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