RESUMEN
Analysis of the dynamic instabilities of periodic waves in a one-dimensional excitable ring medium demonstrates that driven oscillations of a pulse width display different oscillatory behavior at different values of stimulation frequency. Initial periodicity evolves to quasiperiodic dynamics when the propagation speed of a pulse approaches its minimal value determined by the dispersion relation of a medium.
Asunto(s)
Modelos Biológicos , Modelos Químicos , Simulación por Computador , Dinámicas no Lineales , TermodinámicaRESUMEN
We introduce a segmentation control method to sustain chaotic transients in dynamical systems. The sustained transient can be tracked as a system parameter is substantially varied, allowing sustained chaotic transients far away from crisis parameter values. The method is applied to a chaotic CO2 laser as well as to a hyperchaotic continuum mechanics model.
RESUMEN
We consider a dynamics model of lasing microcavities, a class of optical resonators (1-10 &mgr;m in diameter) used in microlasers and for optical coupling of optical fibers. Inside such a cavity light circulates around the perimeter and is trapped by internal reflection. This is known as "whispering gallery" or high-Q modes. The cavity is a deformable cylindrical (or spherical) dielectric and at certain deformations light can escape by refraction. The quality of the resonator or Q factor, is defined as Q=omegatau, where tau is the escape time and omega is the frequency of light. We show that by appropriately deforming the cavity, the Q factor can be controlled by prolonging or shortening the average length of time spent by light trajectories inside the cavity.