RESUMO
Multimode lasers display various behaviors caused by the asymmetry between the modes belonging to orthogonal polarizations. We discuss dynamical independence, clustering, and grouping in a solid state laser with intracavity second harmonic generation, and show that these effects result from unstable cycles lying within their invariant planes. These invariant planes are dynamically independent. The sequential or random itinerancy of limit unstable cycles lying within the invariant planes explains most of the effects caused by asymmetry.
RESUMO
Synchronization due to a weak global coupling with time delay in a semiconductor laser array is investigated both in the cw and self-pulsing regimes. A generalized form of the Kuramoto phase equations is derived and discussed analytically. The time delay is shown to induce in-phase synchronization in all dynamical regimes. Another form of synchronization is found which leads to local extinction of self-pulsing in the array.
RESUMO
We study, analytically and numerically, the effect of frequency detunings and relaxation processes in laser media on stability and bifurcations of dissipative optical localized structures (DOLS's) in a transversely one-dimensional laser with a saturable absorber. The approximate envelope equation, with an intensity dependent effective coefficient of the diffusion, is derived. Andronov-Hopf bifurcations resulting from frequency detuning and leading to oscillatory DOLS's are analyzed numerically. A numerical and analytical study of bifurcations of transversely motionless DOLS's in a laser with finite relaxation rates of amplifying and absorbing media is performed. New types of DOLS's are found, including those moving with a large transverse velocity and those moving with a periodically oscillating transverse velocity. Hysteresis between different types of DOLS's is demonstrated.
