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Haifa, Israel

Bandres M.A.,National Institute of Astrophysics, Optics and Electronics | Alonso M.A.,University of Rochester | Kaminer I.,Solid State Institute | Segev M.,Solid State Institute
Optics Express | Year: 2013

We present a general theory of three-dimensional nonparaxial spatially-accelerating waves of the Maxwell equations. These waves constitute a two-dimensional structure exhibiting shape-invariant propagation along semicircular trajectories. We provide classification and characterization of possible shapes of such beams, expressed through the angular spectra of parabolic, oblate and prolate spheroidal fields. Our results facilitate the design of accelerating beams with novel structures, broadening scope and potential applications of accelerating beams. © 2013 Optical Society of America. Source

Dolev I.,Tel Aviv University | Kaminer I.,Solid State Institute | Shapira A.,Tel Aviv University | Segev M.,Solid State Institute | Arie A.,Tel Aviv University
Physical Review Letters | Year: 2012

We present the experimental observation of 1D and 2D self-accelerating nonlinear beams in quadratic media, which are also the first nonlinear self-accelerating beams in any symmetric nonlinearity. Notably, we show that the intensity peaks of the first and second harmonics are asynchronous with respect to one another, but the coupled harmonics exhibit joint acceleration within the nonlinear medium. Finally, we demonstrate the impact of self-healing effects on the jointly accelerating first and second harmonics. © 2012 American Physical Society. Source

Baskin E.,Solid State Institute | Iomin A.,Solid State Institute
Computers and Mathematics with Applications | Year: 2012

The electrostatics properties of composite materials with fractal geometry are studied in the framework of fractional calculus. This consideration establishes a link between fractal geometry of the media and fractional integro-differentiation. The fractional Maxwell equations are obtained, and methods of fractional calculus are employed to obtain analytical expressions of the electric field inside the fractal composite structures. © 2011 Elsevier Ltd. All rights reserved. Source

Fleischer A.,Solid State Institute | Fleischer A.,ORT Braude College | Kfir O.,Solid State Institute | Diskin T.,Solid State Institute | And 2 more authors.
Nature Photonics | Year: 2014

The roles of energy, momentum and orbital angular momentum conservation in high-harmonic generation were studied in the past. Here, we explore the role of spin angular momentum in high-harmonic generation by experimentally generating high harmonics of bichromatic elliptically polarized pump beams that interact with isotropic media. We explain qualitatively many observed intricate selection rules with a model that includes spin conservation in the conversion of many pump photons into a single photon. However, we also observe unequivocal deviations from this model, indicating that emission of an elliptically polarized high-energy photon is accompanied by an additional excitation (radiative or electronic). The presented results are also important for applications, because our system exhibits full control over the polarization of the harmonics, from circular through elliptical to linear polarization, without compromising the efficiency of the process. This work paves the way for a broad range of applications with high-harmonic generation, including ultrafast circular dichroism of molecules and magnetic materials. © 2014 Macmillan Publishers Limited. Source

Shechtman Y.,Solid State Institute | Eldar Y.C.,Israel Electric | Szameit A.,Solid State Institute | Segev M.,Solid State Institute
Optics Express | Year: 2011

We demonstrate that sub-wavelength optical images borne on partially-spatially-incoherent light can be recovered, from their far-field or from the blurred image, given the prior knowledge that the image is sparse, and only that. The reconstruction method relies on the recently demonstrated sparsity-based sub-wavelength imaging. However, for partially-spatially- incoherent light, the relation between the measurements and the image is quadratic, yielding non-convex measurement equations that do not conform to previously used techniques. Consequently, we demonstrate new algorithmic methodology, referred to as quadratic compressed sensing, which can be applied to a range of other problems involving information recovery from partial correlation measurements, including when the correlation function has local dependencies. Specifically for microscopy, this method can be readily extended to white light microscopes with the additional knowledge of the light source spectrum. © 2011 Optical Society of America. Source

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