Quantum aspects of nonlinear optical patterns

While the discussion of quantum phenomena is traditionally focussed on the case of microscopic systems with one or few particles or quanta, the analysis of quantum effects in macroscopic or mesoscopic systems is presently of outstanding interest. Nonlinear optical patterns1 offer a very appropriate framework for this kind of study. These patterns are formed in the configuration of the electric field in planes orthogonal to the direction of propagation, when the radiation interacts with a nonlinear medium. With respect to other fields which are more traditional with respect to the study of patterns formation (e.g. hydrodynamics, nonlinear chemical reactions, biology etc.) optics presents the special feature that macroscopic systems can display relevant quantum effects, even at room temperature.