We study theoretically and experimentally the modulational instability of broad optical beams in photorefractive nonlinear media. The angular dependence of the growth rate of periodic perturbations is calculated. Our findings are confirmed by experimental measurements on a strontium barium niobate photorefractive crystal.

We study the propagation and localization of light beams in azimuthally modulated Bessel photonic lattices induced optically in photorefractive crystals; such lattices resemble highly nonlinear micro-structured fibres. We report on the experimental observation of discrete diffraction, nonlinear localization, and subsequent formation of spatial solitons. Our experimental results are confirmed by...

 Based on some stationary periodic solutions and stationary soliton solutions, one studies the general solution for the relative lax system, and a number of exact solutions to the Korteweg-de Vries (KdV) equation are first constructed by the known Darboux transformation, these solutions include double and triple singular periodic solutions as well as singular soliton solutions whose amplitude d...

PURPOSE We investigated the keratocyte response and stromal remodeling after corneal incision and photorefractive keratectomy to understand the histophysiological and immunohistochemical differences between these two types of surgery. METHODS Corneal incision or photorefractive keratectomy was performed in rabbits or rats. Then we chronologically observed the histological changes and the chan...

In the last two decades, corneal laser surgery has become a common procedure to correct medium-low refractive defects. It consists of reshaping geometry by means in order present error. this work, we compare opto-mechanical performance procedures: Photorefractive Keratectomy (PRK) and Small Incision Lenticule Extraction (SMILE).

There are periodic soliton resonances in interactions between two periodic solitons and between periodic soliton and another kind of soliton. A close relation exists between the periodic soliton resonance and soliton instability to transverse disturbances. It is shown that the instability occurred in the line soliton is relaxed by emission of the periodic soliton and the periodic soliton resona...

We review work on computing with solitons, from the discovery of solitons in cellular au-tomata, to an abstract model for particle computation (particle machines), to information transfer in collisions of (continuum) optical solitons, to state transformations in collisions of Manakov (vector) solitons. We conclude by discussing open problems and the prospects for practical applications using op...

We study composite spatial optical solitons supported by two-wave mutual focusing induced by cross-phase modulation in Kerr-like nonlinear media. We find the families of both singleand two-hump solitons and discuss their properties and stability. We also reveal remarkable similarities between recently predicted holographic solitons in photorefractive media and parametric solitons in quadratic n...

We study spatially localized optical vortices created by self-trapping of partially incoherent light with a phase dislocation in a biased photorefractive crystal. In contrast to a decay of coherent self-trapped vortex beams due to the azimuthal modulational instability, the incoherent vortices are stabilized for large values of the spatial incoherence; this was confirmed by experiment. We analy...

Exciton effects on conjugated polymers and the resulting optical nonlinearities are investigated in soliton lattice states. We use the Su-Schrieffer-Heeger model with long-range Coulomb interactions for electrons. The thirdharmonic generation (THG) at off-resonant frequencies is calculated as functions of the soliton concentration and the chain length of the polymer. The magnitude of the THG wi...