Optica no lineal: dinàmica de la radiació làser en ressonadors actius i en estructures periòdiques; generació d'harmònics

As a continuation of two previous coordinated projects, in this project we intend to develop a theoretical and experimental study in three topics of great current interest in the field of nonlinear optics. The objectives in every one of these topics are the following: a) laser dynamics. Study of the spatial and temporal characteristics of the emission of three -or more- level laser systems, in both the stable and unstable regimes. These are more general systems than the ordinary lasers, that operate in two level schemes, and include new types of lasers such as cascade lasers, two photon lasers, the optically pumped lasers, and lasers without inversion; b) propagation of laser light in unidimensional superlattices. The nonlinear radiation-matter interaction may be strongly altered in systems where the multiple coherent scattering results in the existence of localiced modes. In this projec