SPONTANEOUS PATTERN-FORMATION IN NONLINEAR-OPTICAL SYSTEMS

Some of the pattern formation and related processes which occur in non linear optical systems are described. Among such systems liquid crysta l devices are prominent, because they can exhibit very large optical n onlinearity, making it relatively easy to achieve significant nonlinea r effects over large areas. A Kerr slice with single feedback mirror f orms hexagonal patterns for plane waves, but its pattern-forming and d ynamic properties change significantly for gaussian beam input. Liquid crystal light valve feedback loops are seen to be closely related to the single-mirror system, and are used in some striking recent experim ents. Other pattern-forming systems, such as lasers, are briefly revie wed.