We present an iterative method for simulating beam propagation in nonlinear media using Hamiltonian ray tracing. The Wigner distribution function of the input beam is computed at the entrance plane and is used as the initial condition for solving the Hamiltonian equations. Examples are given for the study of periodic self-focusing, spatial solitons, and Gaussian-Schell model in Kerr-effect medi...

We study a nonlinear integral equation that is a necessary condition on the equilibrium phase space distribution function of stored, colliding electron beams. It is analogous to the Ha¨ıssinski equation, being derived from Vlasov-Fokker-Planck theory, but is quite different in form. The equation is analyzed for the case of the Chao-Ruth model of the beam-beam interaction in one degree of freedo...

| In our eeort to meet an increasing demand for more accurate and realistic nonlinear optics simulations, we have developed a nonlinear hybrid vector nite element method (NL-HVFEM) to study different phenomena due to wave propagation in waveg-uides lled with nonlinear Kerr-type media. Contrary to the most existing scalar models, the NL-HVFEM approach is based upon the vector Helmholtz equation ...

Self-phase modulation of continuous wave argon-ion laser beam by a medium containing silicon nanocrystallites is reported here. Refractive index of nanocrystallites shows nonlinear behavior with the intensity of probing laser beam when size of nanocrystallites is decreased below 8 nm. A simple quantitative explanation for the observed optical fringes is given in terms of distribution of sizes o...

A nonlinear acoustic effect is a sensitive tool to detect a micro-scale crack or early stage of cracking during the fatigue process. The damage produces a nonlinear stress-strain relationship, and the nonlinearity can be measured by a higher harmonic component in the frequency domain. The greater the damage, the larger the level of a nonlinearity, which can be used for the diagnosis of micro-cr...

In the present study, nonlinear free vibration behavior of nanobeam subjected to magnetic field is investigated based on Eringen’s nonlocal elasticity and Euler–Bernoulli beam theory. The Hamilton’s principal is adopted to derive the governing equations together with Euler–Bernoulli beam theory and the von-Kármán’s nonlinear strain–displacement relationships. An approximate analytical solution ...

We report on experimental and theoretical studies of a photorefractive ring resonator pumped by a 1.06 mm beam and injected with a weak, external, seeding beam. The competition between the two dominant gratings that form inside the photorefractive crystal leads to characteristic periodic oscillations in the intensity of the resonating beam, which originate from the frequency difference between ...

there are several techniques in use for non-linear refractive index measurement, namely, interferometric techniques, in which conventional inter-ferometers are used, degenerate for wave mixing (dfwm), and z-scan, each of these techniques suffers from some shortcmings. for example conventional interferometers like fabry-perot and twyman-green need high quality optical components, unwanted reflec...

this paper describes experimental and numerical investigations on two specimens of frames composed of steel reinforced concrete beam and angle-steel concrete column under horizontal low cyclic loading. based on the test results, the relationship curves of the horizontal load-displacement and the failure modes are acquired. meanwhile the hysteretic behaviors, skeleton curves, stiffness degradati...

We report direct high resolution observation of nonlinear steepened plasma waves excited in the wake of an intense, self-pinched electron beam. Oscillations in both accelerating and deflecting fields are measured, and analyzed in the context of linear and nonlinear plasma wave theory. The degree of nonlinearity in the wakr-fields is shown to be consistent with analytical predictions of the beam...