Benjamin-Feir-type instability in a saturated ferrite: Transition between focusing and defocusing regimes for polarized electromagnetic waves

Nonlinear transverse standing spin wave modes of a magnetic film

We derive an asymptotic model for wave propagation across a ferromagnetic film, neglecting anisotropy and damping, close to the ferromagnetic resonance. The resulting model is a nonlinear Schrödinger equation, which can be either focusing or defocussing, depending on the magnitude and direction of the external magnetic field. We use it to compute the nonlinear eigenmodes of standing spin waves, that can be excited in the film; the eigenmodes can be expressed using Jacobi's elliptic functions. It is shown that their frequency spectrum varies with the amplitude of the modes.

Soliton interactions between multivalued localized waveguide channels within ferrites

In this paper, we investigate both analytically and numerically the localized multivalued waveguide channels-the loop solitons-dynamics within a ferrite slab. In the starting point of the work, we solve in detail the initial value problem of the system while unveiling the existence of multivalued waveguide channels solutions. Paying particular interest to the nonlinear scattering among these excitations, we study extensively the different kinds of interacting features between these localized waves alongside the depiction of their energy densities. As a result, we find that the interactions can be attractive or repulsive depending strongly on the ratio of the amplitudes of the interacting structures. In the wake of these results, we address some physical implications, accordingly.

Short waves in ferromagnetic media

We discuss the propagation of nonlinear electromagnetic short waves in a magnetically saturated ferromagnetic thick film. The sample is magnetized to saturation by a field perpendicular to both the film plane and the propagation direction. A (2+1) dimensional asymptotic model equation generalizing the sine-Gordon one is derived. Line soliton solutions are exhibited; their stability condition is derived. When unstable, line solitons decay into stable two-dimensional lumps, which are studied both numerically and analytically.

Single-oscillation two-dimensional solitons of magnetic polaritons

The propagation of bulk polaritons in ferromagnetic slab is considered through a short-wavelength approximation. Neither the damping nor the demagnetizing field do affect essentially the propagation and stability of the line soliton. The stable line soliton may be destroyed by background instability: the latter is suppressed in a narrow strip. The unstable line soliton decays into lumps, which can be described both numerically and through a variational approach. Lump interactions are mentioned.

Polarization switching in a planar optical waveguide

The multiscale expansion formalism is applied to the study of nonlinear planar optical waveguides. It allows us to describe the linear and nonlinear propagation for both transverse electric and transverse magnetic modes, and the interaction between them. An accurate computation of the nonlinear self- and cross-phase modulation coefficients allows one to give account of the polarization switching which has been observed experimentally.

Nonlinear short-wave propagation in ferrites

In this paper we discuss the propagation of nonlinear electromagnetic short waves in ferromagnetic insulators. We show that such propagation is perpendicular to an externally applied field. In the nonlinear regime we determine various possible propagation patterns: an isolated pulse, a modulated sinusoidal wave, and an asymptotic two-peak wave. The mathematical structure underlying the existence of these solutions is that of the integrable sine-Gordon equation.