Nonlinear Optics

Abstract We present an unified overview and classification of the main nonlinear optical effects and the underlying nonlinear optical interactions. The physical origin of these effects is analyzed and related to material features and their behavior, their characteristics and efficiency are discussed in terms of the nonlinear propagation equations. Some aspects related to nonlinear optical materials and devices are presented and connections with quantum optics, nonlinear spectroscopy and optoelectronics are stressed.