DOMAIN COEXISTENCE IN 2-DIMENSIONAL OPTICAL-PATTERNS

We give evidence of coexisting transverse patterns of different symmet ry in an optical beam circulating in a loop which contains a nonlinear medium. The symmetry of the patterns is controlled by the azimuthal r otation introduced in the feedback loop (nonlocality), while the compe tition is ruled by the input intensity which determines the distance f rom threshold (nonlinearity). Domains corresponding to patterns with d ifferent wave vectors (either different wavelength or different orient ation) coexist, nucleating and moving. This gives rise to a complex sp atiotemporal dynamics which is characterized by means of suitable coll ective indicators.