69 research outputs found
Frozen Waves: Stationary optical wavefields with arbitrary longitudinal shape, by superposing equal-frequency Bessel beams
In this paper it is shown how one can use Bessel beams to obtain a stationary
localized wavefield with high transverse localization, and whose longitudinal
intensity pattern can assume any desired shape within a chosen interval 0 < z <
L of the propagation axis. This intensity envelope remains static, i.e., with
velocity v=0; and because of this we call "Frozen Waves" such news solutions to
the wave equations (and, in particular, to the Maxwell equations). These
solutions can be used in many different and interesting applications, as
optical tweezers, atom guides, optical or acoustic bistouries, various
important medical purposes, etc.Comment: LaTeX file (10 pages, including 2 sets of two Figures
Spatiotemporal Amplitude and Phase Retrieval of Bessel-X pulses using a Hartmann-Shack Sensor
We propose a new experimental technique, which allows for a complete
characterization of ultrashort optical pulses both in space and in time.
Combining the well-known Frequency-Resolved-Optical-Gating technique for the
retrieval of the temporal profile of the pulse with a measurement of the
near-field made with an Hartmann-Shack sensor, we are able to retrieve the
spatiotemporal amplitude and phase profile of a Bessel-X pulse. By following
the pulse evolution along the propagation direction we highlight the
superluminal propagation of the pulse peak
Focused X-shaped (Superluminal) pulses
The space-time focusing of a (continuous) succession of localized X-shaped
pulses is obtained by suitably integrating over their speed, i.e., over their
axicon angle, thus generalizing a previous (discrete) approach. First, new
Superluminal wave pulses are constructed, and then tailored in such a wave to
get them temporally focused at a chosen spatial point, where the wavefield can
reach for a short time very high intensities. Results of this kind may find
applications in many fields, besides electromagnetism and optics, including
acoustics, gravitation, and elementary particle physics.
PACS nos.: 41.20.Jb; 03.50.De; 03.30.+p; 84.40.Az; 42.82.Et; 83.50.Vr;
62.30.+d; 43.60.+d; 91.30.Fn; 04.30.Nk; 42.25.Bs; 46.40.Cd; 52.35.Lv.
Keywords: Localized solutions to Maxwell equations; Superluminal waves;
Bessel beams; Limited-diffraction pulses; Finite-energy waves; Electromagnetic
wavelets; X-shaped waves; Electromagnetism; Microwaves; Optics; Special
relativity; Localized acoustic waves; Seismic waves; Mechanical waves;
Elementary particle physics; Gravitational wavesComment: Latex file, with 6 Figure
Modeling Of Space-time Focusing Of Localized Nondiffracting Pulses
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)In this paper we develop amethod capable of modeling the space-time focusing of nondiffracting pulses. These pulses can possess arbitrary peak velocities and, in addition to being resistant to diffraction, can have their peak intensities and focusing positions chosen a priori. More specifically, we can choose multiple locations (spatial ranges) of space and time focalization; also, the pulse intensities can be chosen in advance. The pulsed wave solutions presented here can have very interesting applications in many different fields, such as free-space optical communications, remote sensing, medical apparatus, etc.944Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2015/26444-8]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [312376/2013-8]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Superluminal Localized Solutions To Maxwell Equations Propagating Along A Normal-sized Waveguide.
We show that localized (nonevanescent) solutions to Maxwell equations exist, which propagate without distortion along normal waveguides with superluminal speed.6406660
Propagation of time-truncated Airy-type pulses in media with quadratic and cubic dispersion
In this paper, we describe analytically the propagation of Airy-type pulses
truncated by a finite-time aperture when second and third order dispersion
effects are considered. The mathematical method presented here, based on the
superposition of exponentially truncated Airy pulses, is very effective,
allowing us to avoid the use of time-consuming numerical simulations. We
analyze the behavior of the time truncated Ideal-Airy pulse and also the
interesting case of a time truncated Airy pulse with a "defect" in its initial
profile, which reveals the self-healing property of this kind of pulse
solution.Comment: 9 pages. 5 figure
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