A. V. Mamaev

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We analyze the evolution of ͑111͒ dimensional dark stripe beams in bulk media with a photorefractive nonlinear response. These beams, including solitary wave solutions, are shown to be unstable with respect to symmetry breaking and formation of structure along the initially homogeneous coordinate. Experimental results show the complete sequence of events(More)
We report on selection and stabilization of transverse optical patterns in a feedback mirror experiment. Amplitude filtering in the Fourier plane is used to select otherwise unstable spatial patterns. Optical turbulence observed for nonlinearities far above the pattern formation threshold is stabilized by low-pass filtering of the optical power spectrum.(More)
We present a theoretical and experimental study of the propagation, decay, and interaction of optical vortices in media with an anisotropic nonlocal nonlinearity. The initial stage of decay of a circular vortex is characterized by charge dependent rotation, and stretching of the vortex. Our results suggest that a compact vortex of unit topological charge(More)
We present an experimental and theoretical study of the decay of high order optical vortices in media with an anisotropic nonlocal nonlinearity. Vortices with charge n decay into an aligned array of n vortices of unit charge. Vortical excitations with quantized circulation appear in superfluids, superconductors, and nonlinear optics in the presence of a(More)
We study pattern formation that is due to modulational instability of noncollinear counterpropagating beams. Angular misalignment of the pumps over a broad range leads to the generation of lines oriented perpendicular to the plane of the pump beams. A theoretical expression for the angular separation of the lines is in close agreement with observations.(More)
PACS. 42.65Jx – Beam trapping, self-focusing, and thermal blooming. PACS. 42.65Tg – Optical solitons; nonlinear guided waves. PACS. 42.65Hw – Phase conjugation, optical mixing, and photorefractive effect. Abstract. – We present the theory and the experimental observation of break-up of two-dimensional bright spatial solitons propagating in a(More)
PACS. 42.65Tg – Optical solitons; nonlinear guided waves. PACS. 42.65Jx – Beam trapping, self-focusing, and thermal blooming. PACS. 42.65Hw – Phase conjugation, optical mixing, and photorefractive effect. Abstract. – We investigate self-focusing in bulk media with anisotropic nonlocal photorefrac-tive response. Analytical results demonstrate the possibility(More)
We find and analyze bound dipole solitary solutions in media with anisotropic nonlocal photorefractive material response. The dipole solutions consist of two elliptically shaped Gaussian-type beams separated by several diameters, and with a ␲ phase shift between their fields. Spatial evolution of two initially round Gaussian beams and their convergence to(More)