Solitons in Nonlinear Media with an Infinite Range of Nonlocality: First Observation of Coherent Elliptic Solitons and of Vortex-Ring Solitons

We present an experimental study on wave propagation in highly nonlocal optically nonlinear media, for which far-away boundary conditions significantly affect the evolution of localized beams. As an example, we set the boundary conditions to be anisotropic and demonstrate the first experimental observation of coherent elliptic solitons. Furthermore, exploiting the natural ability of such nonlinearities to eliminate azimuthal instabilities, we perform the first observation of stable vortex-ring solitons. These features of highly nonlocal nonlinearities affected by far-away boundary conditions open new directions in nonlinear science by facilitating remote control over soliton propagation

Dark stationary matter waves via parity-selective filtering in a Tonks-Girardeau gas

We propose a scheme for observing dark stationary waves in a Tonks-Girardeau (TG) gas. The scheme is based on parity-selective dynamical filtering of the gas via a time-dependent potential, which excites the gas from its ground state towards a desired specially-tailored many-body state. These excitations of the TG gas are analogous to linear partially coherent nondiffracting beams in optics, as evident from the mapping between the quantum dynamics of the TG gas and the propagation of incoherent light in one-dimensional linear photonic structures

Observation of 2nd band vortex solitons in 2D photonic lattices

We demonstrate second-band bright vortex-array solitons in photonic lattices. This constitutes the first experimental observation of higher-band solitons in any 2D periodic system. These solitons possess complex intensity and phase structures, yet they can be excited by a simple highly-localized vortex-ring beam. Finally, we show that the linear diffraction of such beams exhibits preferential transport along the lattice axes

Discrete diffraction and spatial gap solitons in photovoltaic LiNbO3 waveguide arrays

We investigate, experimentally and theoretically, light propagation in one-dimensional waveguide arrays exhibiting a saturable self-defocusing nonlinearity. We demonstrate low-intensity “discrete diffraction”, and the high-intensity formation of spatial gap solitons arising from the first band of the transmission spectrum. The waveguide arrays are fabricated by titanium in-diffusion in a photorefractive copper-doped lithium niobate crystal, and the optical nonlinearity arises from the bulk photovoltaic effect

Grating-Mediated Wave Guiding And Holographic Solitons

We describe experimental and theoretical results of research on a new type of waveguide, the so-called grating-mediated waveguide (GMW) recently reported by our group. This waveguide structure relies on Bragg diffractions from a 1D grating giving rise to wave guiding in the direction normal to the grating wave vector. The structure consists of a shallow 1D grating having a bell- or trough-shaped amplitude in the confinement direction. We provide the theoretical analysis of the underlying wave-guiding mechanism along with experimental evidence for both the bell- and the trough-shaped waveguides. We investigate the robustness of grating-mediated wave guiding and suggest more elaborate, 2D structures, such as a GMW superlattice and a grating-mediated ring waveguide. Finally we discuss the relation between grating-mediated wave guiding and holographic solitons, which are the beams that are self-trapped solely by virtue of their jointly induced grating. © 2005 Optical Society of America

Nondiffracting Beams In Periodic Media

We present nondiffracting beams in 2D periodic systems. We show that these beams may be associated with different bands in the transmission spectrum of the system and with different symmetry points of the Brillouin zone. © 2005 Optical Society of America

Nondiffracting Beams In Periodic Media

We present nondiffracting beams in 2D periodic systems. We show that these beams may be associated with different bands in the transmission spectrum of the system and with different symmetry points of the Brillouin zone. © 2005 Optical Society of America

Nondifiracting Beams In Periodic Media

We identify nondiffracting beams in two-dimensional periodic systems, exhibiting symmetry properties and phase structure characteristic of the band(s) they are associated with. © 2005 Optical Society of America

Hofstadter butterflies in nonlinear Harper lattices, and their optical realizations

The ubiquitous Hofstadter butterfly describes a variety of systems characterized by incommensurable periodicities, ranging from Bloch electrons in magnetic fields and the quantum Hall effect to cold atoms in optical lattices and more. Here, we introduce nonlinearity into the underlying ( Harper) model and study the nonlinear spectra and the corresponding extended eigenmodes of nonlinear quasiperiodic systems. We show that the spectra of the nonlinear eigenmodes form deformed versions of the Hofstadter butterfly and demonstrate that the modes can be classified into two families: nonlinear modes that are a \u27continuation\u27 of the linear modes of the system and new nonlinear modes that have no counterparts in the linear spectrum. Finally, we propose an optical realization of the linear and nonlinear Harper models in transversely modulated waveguide arrays, where these Hofstadter butterflies can be observed. This work is relevant to a variety of other branches of physics beyond optics, such as disorder-induced localization in ultracold bosonic gases, localization transition processes in disordered lattices, and more