Photoinduced generation of the second harmonic in centrosymmetric media

This review deals with the photoinduced generation of the second harmonic in centrosymmetric media. A brief account is given of the main results of the reported investigations. The models proposed to describe the effect are discussed. The principles for experimental separation of the contributions of the various mechanisms are put forward and the results of the relevant experiments are described. A detailed phenomenological description of the photogalvanic mechanism is given and an experimental confirmation of this mechanism is reported.