The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Demetrios N. Christodoulides - One of the best experts on this subject based on the ideXlab platform.
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modulation instability and pattern formation in spatially incoherent Light Beams
Science, 2000Co-Authors: Detlef Kip, Marin Soljacic, Mordechai Segev, Eugenia D Eugenieva, Demetrios N. ChristodoulidesAbstract:We report on the experimental observation of modulation instability of partially spatially incoherent Light Beams in noninstantaneous nonlinear media and show that in such systems patterns can form spontaneously from noise. Incoherent modulation instability occurs above a specific threshold that depends on the coherence properties (correlation distance) of the wave packet and leads to a periodic train of one-dimensional filaments. At a higher value of nonlinearity, the incoherent one-dimensional filaments display a two-dimensional instability and break up into self-ordered arrays of Light spots. This discovery of incoherent pattern formation reflects on many other nonlinear systems beyond optics. It implies that patterns can form spontaneously (from noise) in diverse nonlinear many-body systems involving weakly correlated particles, such as atomic gases at (or near) Bose-Einstein condensation temperatures and electrons in semiconductors at the vicinity of the quantum Hall regime.
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self trapping of dark incoherent Light Beams
Science, 1998Co-Authors: Zhigang Chen, Mordechai Segev, Matthew Mitchell, Tamer H Coskun, Demetrios N. ChristodoulidesAbstract:“Dark Beams” are nonuniform optical Beams that contain either a one-dimensional (1D) dark stripe or a two-dimensional (2D) dark hole resulting from a phase singularity or an amplitude depression in their optical field. Thus far, self-trapped dark Beams (dark solitons) have been observed using coherent Light only. Here, self-trapped dark incoherent Light Beams (self-trapped dark incoherent wavepackets) were observed. Both dark stripes and dark holes nested in a broad partially spatially incoherent wavefront were self-trapped to form dark solitons in a host photorefractive medium. These self-trapped 1D and 2D dark Beams induced refractive-index changes akin to planar and circular dielectric waveguides. The experiments introduce the possibility of controlling high-power coherent laser Beams with low-power incoherent Light sources such as Light emitting diodes.
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theory of self trapped spatially incoherent Light Beams
Physical Review Letters, 1997Co-Authors: Matthew Mitchell, Mordechai Segev, Tamer H Coskun, Demetrios N. ChristodoulidesAbstract:We present a modal theory of self-trapping spatially incoherent Light Beams in any general nonlinear media. We find that a self-trapped incoherent beam induces a multimode waveguide which guides the beam itself by multiply populating the guided modes. The self-trapping process alters the statistics of the incoherent beam, rendering it localized. We find the conditions for self-trapping (``existence region'' in parameter space) and the correlation function of the incoherent self-trapped beam.
Mo Mojahedi - One of the best experts on this subject based on the ideXlab platform.
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controlling the topological charge of twisted Light Beams with propagation
Physical Review A, 2016Co-Authors: Ahmed H Dorrah, Michel Zambonirached, Mo MojahediAbstract:Light Beams with azimuthal phase dependence [$exp(i \ell\phi)$] carry orbital angular momentum (OAM) which differs fundamentally from spin angular momentum (SAM) associated with polarization. Striking difference between the two momenta is manifested in the allowable values: where SAM is limited to $\hbar k_0$ per photon, the OAM has unbounded value of $\ell\hbar$ per photon ($\ell$ is integer), thus dramatically exceeding the value of SAM \cite{Ref1,Ref2, Ref3}. OAM has thus been utilized in optical trapping \cite{Ref4}, imaging\cite{Ref2}, and material processing \cite{Ref5}. Furthermore, the unbounded degrees-of-freedom in OAM states have been deployed in data communications \cite{Ref6}. Here, we report an \textit{exceptional} behavior for a class of Light Beams---known as Frozen Waves (FWs)---whose intensity and azimuthal phase profiles can be controlled along the propagation direction, at will. Accordingly, we generate rotating Light patterns that can change their sense of rotation and order of phase twist with propagation. Manipulating OAM along the beam axis can open new directions in optical science and its applications.
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controlling the topological charge of twisted Light Beams with propagation
Physical Review A, 2016Co-Authors: Ahmed H Dorrah, Michel Zambonirached, Mo MojahediAbstract:We report on advanced manipulation of a class of Light Beams---known as frozen waves---that carry orbital angular momentum and whose intensity and topological charge (sign and magnitude) can be controlled along the propagation direction, at will. Accordingly, we demonstrate rotating Light structures that change their sense of rotation and order of phase twist with propagation. This degree of longitudinal control can address many challenges in dense data communications, optical trapping and micromanipulation, and remote sensing and imaging, to name a few.
Mordechai Segev - One of the best experts on this subject based on the ideXlab platform.
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modulation instability and pattern formation in spatially incoherent Light Beams
Science, 2000Co-Authors: Detlef Kip, Marin Soljacic, Mordechai Segev, Eugenia D Eugenieva, Demetrios N. ChristodoulidesAbstract:We report on the experimental observation of modulation instability of partially spatially incoherent Light Beams in noninstantaneous nonlinear media and show that in such systems patterns can form spontaneously from noise. Incoherent modulation instability occurs above a specific threshold that depends on the coherence properties (correlation distance) of the wave packet and leads to a periodic train of one-dimensional filaments. At a higher value of nonlinearity, the incoherent one-dimensional filaments display a two-dimensional instability and break up into self-ordered arrays of Light spots. This discovery of incoherent pattern formation reflects on many other nonlinear systems beyond optics. It implies that patterns can form spontaneously (from noise) in diverse nonlinear many-body systems involving weakly correlated particles, such as atomic gases at (or near) Bose-Einstein condensation temperatures and electrons in semiconductors at the vicinity of the quantum Hall regime.
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self trapping of dark incoherent Light Beams
Science, 1998Co-Authors: Zhigang Chen, Mordechai Segev, Matthew Mitchell, Tamer H Coskun, Demetrios N. ChristodoulidesAbstract:“Dark Beams” are nonuniform optical Beams that contain either a one-dimensional (1D) dark stripe or a two-dimensional (2D) dark hole resulting from a phase singularity or an amplitude depression in their optical field. Thus far, self-trapped dark Beams (dark solitons) have been observed using coherent Light only. Here, self-trapped dark incoherent Light Beams (self-trapped dark incoherent wavepackets) were observed. Both dark stripes and dark holes nested in a broad partially spatially incoherent wavefront were self-trapped to form dark solitons in a host photorefractive medium. These self-trapped 1D and 2D dark Beams induced refractive-index changes akin to planar and circular dielectric waveguides. The experiments introduce the possibility of controlling high-power coherent laser Beams with low-power incoherent Light sources such as Light emitting diodes.
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theory of self trapped spatially incoherent Light Beams
Physical Review Letters, 1997Co-Authors: Matthew Mitchell, Mordechai Segev, Tamer H Coskun, Demetrios N. ChristodoulidesAbstract:We present a modal theory of self-trapping spatially incoherent Light Beams in any general nonlinear media. We find that a self-trapped incoherent beam induces a multimode waveguide which guides the beam itself by multiply populating the guided modes. The self-trapping process alters the statistics of the incoherent beam, rendering it localized. We find the conditions for self-trapping (``existence region'' in parameter space) and the correlation function of the incoherent self-trapped beam.
Lorenzo Marrucci - One of the best experts on this subject based on the ideXlab platform.
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measuring the complex orbital angular momentum spectrum and spatial mode decomposition of structured Light Beams
Optica, 2017Co-Authors: Alessio Derrico, Raffaele Damelio, Bruno Piccirillo, Filippo Cardano, Lorenzo MarrucciAbstract:Light Beams carrying orbital angular momentum are key resources in modern photonics. In many applications, the ability to measure the complex spectrum of structured Light Beams in terms of these fundamental modes is crucial. Here we propose and experimentally validate a simple method that achieves this goal by digital analysis of the interference pattern formed by the Light beam and a reference field. Our approach allows one to also characterize the beam radial distribution, hence retrieving the entire information contained in the optical field. Setup simplicity and reduced number of measurements could make this approach practical and convenient for the characterization of structured Light fields.
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measuring the complex orbital angular momentum spectrum and spatial mode decomposition of structured Light Beams
arXiv: Optics, 2017Co-Authors: Alessio Derrico, Raffaele Damelio, Bruno Piccirillo, Filippo Cardano, Lorenzo MarrucciAbstract:Light Beams carrying orbital angular momentum are key resources in modern photonics. In many applications, the ability of measuring the complex spectrum of structured Light Beams in terms of these fundamental modes is crucial. Here we propose and experimentally validate a simple method that achieves this goal by digital analysis of the interference pattern formed by the Light beam and a reference field. Our approach allows one to characterize the beam radial distribution also, hence retrieving the entire information contained in the optical field. Setup simplicity and reduced number of measurements could make this approach practical and convenient for the characterization of structured Light fields.
Matthew Mitchell - One of the best experts on this subject based on the ideXlab platform.
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self trapping of dark incoherent Light Beams
Science, 1998Co-Authors: Zhigang Chen, Mordechai Segev, Matthew Mitchell, Tamer H Coskun, Demetrios N. ChristodoulidesAbstract:“Dark Beams” are nonuniform optical Beams that contain either a one-dimensional (1D) dark stripe or a two-dimensional (2D) dark hole resulting from a phase singularity or an amplitude depression in their optical field. Thus far, self-trapped dark Beams (dark solitons) have been observed using coherent Light only. Here, self-trapped dark incoherent Light Beams (self-trapped dark incoherent wavepackets) were observed. Both dark stripes and dark holes nested in a broad partially spatially incoherent wavefront were self-trapped to form dark solitons in a host photorefractive medium. These self-trapped 1D and 2D dark Beams induced refractive-index changes akin to planar and circular dielectric waveguides. The experiments introduce the possibility of controlling high-power coherent laser Beams with low-power incoherent Light sources such as Light emitting diodes.
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theory of self trapped spatially incoherent Light Beams
Physical Review Letters, 1997Co-Authors: Matthew Mitchell, Mordechai Segev, Tamer H Coskun, Demetrios N. ChristodoulidesAbstract:We present a modal theory of self-trapping spatially incoherent Light Beams in any general nonlinear media. We find that a self-trapped incoherent beam induces a multimode waveguide which guides the beam itself by multiply populating the guided modes. The self-trapping process alters the statistics of the incoherent beam, rendering it localized. We find the conditions for self-trapping (``existence region'' in parameter space) and the correlation function of the incoherent self-trapped beam.
