Bifurcation magnetic resonance in films with differently oriented crystallographic axes

The magnetization dynamics in single-crystal films with cubic anisotropy has been investigated based on numerical simulation. It is shown that the application of an in-plane bias magnetic field along hard magnetization axes gives rise to an additional (bifurcation) resonance, which is due to the existence of bistability, i.e., two closely located equilibrium magnetization states. The specific features of bifurcation resonance are revealed in films with the three main crystallographic orientations: (100), (110), and (111). Changes in the resonance range and corresponding dynamic modes with a change in the ac field frequency are investigated. States of dynamic bistability and multistability are obtained in the bifurcation resonance range.     

Dynamics of frequency-modulated soliton-like pulses in a longitudinally inhomogeneous active optical waveguide

Conditions of the formation and amplification of frequency-modulated soliton-like pulses in longitudinally inhomogeneous active optical waveguides with anomalous dispersion of group velocities are studied. Group velocity dispersion profiles that are necessary for existence and amplification for active and passive optical waveguides are determined, and the dependences on the distance passed along the waveguide, duration, and chirp of the pulse are established.     

Waveguide interaction between light and an amplified space-charge wave

The collinear interaction of optical waveguide modes is considered in a thin semiconductor layer containing an optical inhomogeneity (space-charge wave) growing along the wave-propagation direction. Coupled-mode equations are solved for the case where interacting waves propagate in the same direction or in opposite directions. The mode conversion efficiency is shown to depend substantially on the space-charge wave amplification with allowance for the detuning from the phase matching condition. The incident and the oppositely propagating modes can be “degenerate,” in which case the modes have the same power over the entire disturbed region.     

Diffraction of light from a stripe domain structure with tilted domain walls

The intensity and polarization parameters of light waves diffracted from a stripe domain structure with tilted domain walls and the magnetic moment in domains oriented parallel to the walls are determined in the approximation of thin layers and linear magnetooptical coupling.     

Hysteresis loops of a periodic multilayered structure with antiferromagnetic coupling

The hysteresis loops of 18° in-plane magnetization reversal in a system of magnetic films with cubic crystallographic anisotropy coupled by the interlayer antiferromagnetic exchange interaction are plotted. The loops correspond to different orientations of the switching field with respect to crystallographic axes. Wasp-waisted loops, loops collapsing in weak fields, and bistable (bifurcation) loops are found.     

Multistability of the Magnetization Reversal of a Nanoparticle with Cubic Anisotropy

JETP Letters - The dynamics of magnetization reversal of a nanoparticle with cubic magnetic anisotropy by a short Gaussian pulse of a magnetic field has been studied. It has been shown that the...     

Waveguide properties of a four-layer planar structure with an absorbing coating layer

An exact solution is obtained and a problem of waveguide light propagation in a scalar asymmetric four-layer waveguide with an absorbing coating layer is analyzed numerically. The periodicity of modal characteristics with change in the coating layer thickness is established. The feasibility of achieving a single-mode light propagation regime at the expense of the absorbing coating layer is demonstrated. Ul'yanovsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 79–85, July, 2000.     

Resonant interaction of light with a banded domain structure

The distinctive features of the interaction of light with a banded domain structure produced by linear magnetooptical effects are discussed. A dispersion law for characteristic circular waves is found which contains regions of forbidden spatial frequencies in which the interaction of light with the structure is of a resonance nature. Dependences of the reflection and transmission coefficients and angle of rotation of the polarization plane on frequency and crystal size are obtained for these regions.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 84–88, March, 1982.