Light field transformation by intracavity four-wave mixing

Advances in the development of nonlinear interference and holographic systems based on four-wave mixing point to great potentialities of these systems for real-time processing and correction of the light fields, formation of the desired space-time structures of laser radiation, image transfer, realization of logic and mathematical operations, creation of bistable devices and adaptive optics elements. This work presents the results of theoretical and experimental studies into the processes of light field transformations upon frequency-nondegenerate four-wave mixing in nonlinear Fabry-Perot interferometer. The principal aim is to develop a theory of intracavity four-wave mixing in complex molecular media in conditions of exhibited internal (scattering from dynamic gratings) and external (resonator) feedback, to determine a mechanism of light field transformations at the dynamic holograms and by nonlinear interferometers, to work out and introduce into practice novel nonlinear-optical methods for the control over characteristics of light beams. For theoretical description of typical experimental situations we used the round-trip model of interferometer adapted for the geometry of four-wave mixing, which can be realized in the scheme of symmetrical oblique incidence of reference and signal beams to the front and back mirrors of cavity. The conditions of magnification of dynamic gratings efficiency due to contribution from multiple interference of reading light beams have been studied experimentally and by means of theoretical modeling.