Doubly resonant Bragg simultons via second-harmonic generation

C. Conti, S. Trillo, and G. Assanto

Phys. Rev. Lett. 78, 2341-2344 (1997)


We predict that the combined effect of quadratic nonlinearity and dispersion induced by a periodic variation of the linear susceptibility can give rise to simultaneous localization of counterpropagating waves at different carrier frequencies, in the form of two envelope solitary waves(i.e., gap or Bragg resonance simultons). Our predictions stemming from an analytical approach are confirmed numerically with finite boundary conditions in a variety of qualitatively different situations.