The aim of our book is to provide a unified and compact vision of the tree of nonlinear optical models and of the wealth of phenomena that can be described by them. In doing that, we adopt the viewpoint of the general field of nonlinear dynamical systems, even if we keep the treatment at a certain level of simplicity, performing an in-depth analysis but avoiding all of the technicalities which are not strictly necessary.

The discussion encompasses static aspects, temporal phenomena and spatial effects, including both those arising in the longitudinal direction in which the light beam propagates and those which occur in the transverse directions. The selected material gathers and organizes a wealth of knowledge scattered in a vast literature from the sixties of the past century to our days.

The volume is subdivided into three parts of decreasing extent. The first seventeen chapters derive from the fundamental laws which govern electromagnetic radiation and matter, a variety of models that describe the radiation-matter interaction both in free propagation and in optical cavities, and discuss mainly the stationary solutions of such models. Most space is devoted to two-level systems, but attention is paid also to parametric systems and to the effects of atomic coherence in multilevel systems. Part II (Chapters 18–25) illustrates the dynamical aspects of lasers and other amplifying or absorbing systems and, in particular, the onset of instabilities that lead to phenomena of spontaneous pulsations and chaos. Part III (Chapters 26–30) deals with the phenomena which arise in the transverse section of light beams, such as Gaussian modes, spontaneous spatial pattern formation and cavity solitons.

The book combines topics that are usually considered in courses on laser physics/quantum electronics and nonlinear optics. The natural attention to the standard laser is extended to other kinds of laser, such as lasers with saturable absorber or injected signal, to other light sources as the optical parametric oscillator and to passive systems that exhibit optical bistability.