Periodic solitary waves for two coupled nonlinear Klein–Gordon and Schr dinger equations

Six new periodic analytic solitary-wave solutions of two coupled nonlinear Klein–Gordon and Schrödinger equations are presented. Besides their application to optical solitary wavepairs due to cross-phase modulation or modal birefringence, their application to the (presently) unphysical regime and the significance of symmetry are discussed. For two related special sets of the two coupled equations, additional possible analytic solutions are presented.