We report the first experimental demonstration of two-dimensional spatial solitary waves in secondorder nonlinear optical material. When an intense optical beam is focused into a phase-matchable second-order nonlinear material, the fundamental and generated second-harmonic fields are mutually trapped as a result of the strong nonlinear coupling which counteracts both diffraction and beam walkoff.

We introduce a novel class of parametric optical solitons supported simultaneously by two second-order nonlinear cascading processes, second-harmonic generation and sum-frequency mixing. We obtain analytical and numerical solutions for three-wave spatial solitons and show that the presence of an additional cascading mechanism can change dramatically the properties and stability of two-wave quad...

The dynamics of pseudo-classical spinning particles in spacetime of gravitational plane waves of general polarization and harmonic profile is studied. The resulting equations of motion are solved exactly and the results are compared with those of the other approaches. The relative accelerations of nearby particles is also calculated. PACS numbers: 04.20.-q, 04.25.-g, 04.30.-Nk

We study the inverse boundary value problem for the time-harmonic elastic waves. We focus on the recovery of the density and assume the sti↵ness tensor to be isotropic. The data are the Dirichlet-to-Neumann map. We establish a Lipschitz type stability estimate assuming that the density is piecewise constant with an underlying domain partitioning consisting of a finite number of subdomains.

Refractive index measurements of uniaxial media at wavelengths in the I-Rspectrum are described. The experimental technique makes use of the birefringence to generate interference between the extraordinary and ordinary waves created after an incident plane polarized wave enters the crystal. The use of harmonic generation to convert I-Rradiations to

A self-trapped laser filament is susceptible to decay-producing radially localized Langmuir waves. A nonlinear interaction of the pump wave with the density oscillation at the Langmuir frequency gives rise to three-halves harmonic emissions. Using a basis-function expansion technique, the emitted power in the backward direction is obtained. It decreases with the increasing size of the filament.

We study the interaction of well-separated oscillating localized structures (oscillons). We show that oscillons emit weakly decaying dispersive waves, which lead to the formation of bound states due to harmonic synchronization. We also show that in optical applications the Andronov-Hopf bifurcation of stationary localized structures leads to a drastic increase in their interaction strength.

It is known that when two fluids flow through a horizontal channel, depending on the relative velocity between the two fluids, two different instability mechanisms can create initial wave disturbances on the interface: the classic Kelvin-Helmholtz instability or shear induced instability. These instability mechanisms, which affect the initial growth of the disturbances on the interface, are wel...

Waveguides can be employed to test nonlinear effects in electrodynamics. We solve Born-Infeld equations for TE waves in a rectangular waveguide. We show that the energy velocity acquires a dependence on the amplitude, and harmonic components appear as a consequence of the nonlinear behavior.

We investigate the evolution of self-guided beams in a chi((2)) medium with a fluctuating phase mismatch between the fundamental wave and its second harmonic, as may occur in particular when the quasi-phase-matching technique is applied. We show that the fluctuations reduce the phase correlation and act as an effective loss to solitary waves.