EVOLUTION AND SWITCHING DYNAMICS OF SOLITARY SPOTS IN NONLINEAR-OPTICAL FEEDBACK-SYSTEMS

We have studied experimentally and numerically spontaneous transvere p attern formation in a single feedback experiment using an optically ad dressable liquid crystal light valve in the polarization mode as a non linear optical element. Scaling behaviour has been found and transitio ns between different types of patterns have been observed which can be easily controlled by the bias voltage of the liquid crystal light val ve. In a certain range of this control parameter we have investigated the evolution of bright solitary spots showing noncritical slowing dow n in the switching characteristics. This dynamical behaviour is relate d to the existence of an unstable branch which separates the basins of attraction of two stable states.