Multiple quasi-phase-matching in a nonperiodic domain-inverted optical superlattice

We theoretically propose a nonperiodic optical superlattice (NOS), in which multiple nonlinear optical parametric processes can be realized simultaneously. The optimal design of the NOS structure is achieved by the combination of stimulated annealing (SA) and genetic algorithm methods. The multiple quasi-phase-matched (QPM) second harmonic generations (SHG's) in NOS's are theoretically investigated. The numerical simulations show that NOS's can be used as a more effective and useful nonlinear optical crystal for multiple nonlinear optical parametric generation