On the response of an oscillatory medium to defect generation

H Zhao, R Friedrich, T Ackemann

Research output: Contribution to journalArticle

Abstract

We investigate the response of a system far from equilibrium close to an oscillatory instability to the induction of phase singularities. We base our investigation on a numerical treatment of the complex Ginzburg-Landau equation (CGLE) in two spatial dimensions, which is considered as an order-parameter equation for lasers and other nonlinear optical systems. Defects are randomly generated by a spatially modulated linear growth rate. In the amplitude-turbulent regime, no qualitative change of behaviour can be detected. Phase-turbulent patterns emerging due to the Benjamin-Feir instability are destroyed by the externally injected defects. One observes either states consisting of spiral structures of various sizes which resemble the vortex glass states of the unperturbed system or a travelling wave pattern containing moving topological defects. In parameter space, both states are separated by a well-defined phase boundary which is close to the line separating convectively from absolutely stable travelling waves.

Original languageEnglish
Pages (from-to)969-973
Number of pages5
JournalApplied Physics B: Lasers and Optics
Volume81
Issue number7
DOIs
Publication statusPublished - Nov 2005

Keywords

  • ginzburg-landau equation
  • optical-pattern formation
  • laser hydrodynamics
  • turbulence
  • vortices

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