NONLINEAR DYNAMICS IN AN OPTICAL-SYSTEM WITH CONTROLLED 2-DIMENSIONALFEEDBACK - BLACK-EYE PATTERNS AND RELATED PHENOMENA

We present experimental and theoretical results of spontaneous optical pattern formation in a nonlinear optical system. The nonlinear optica l system we considered had a controllable phase-only spatial Fourier f ilter placed in the system's diffractive feedback loop. A change in fe edback field spatial spectral component phase resulted in a transition between dynamic regimes, as observed in both experiments and numerics . Patterns originating from interactions between spatial modes belongi ng to different instability bands (black-eye patterns, decagons, etc.) were observed, as well as localized states and shock traveling waves.