Consecutive three-wave interactions in nonlinear optics of periodically inhomogeneous media

A brief review of recent advances in the studies of two coupled three-wave nonlinear optical processes with multiple frequencies, which possess a number of special properties compared to conventional three-wave processes, is presented. The consecutive interactions of co-propagating and counter-propagating light waves in a LiNbO₃ crystal with a regular domain structure are considered. The energy exchange upon consecutive interactions of the waves with frequencies ω, 2ω and 3ω is analysed. The prospects of using consecutive nonlinear optical processes in quantum electronics and nonlinear optics are discussed.