Abstract: In order to get new femtosec;ond-laser an aperiodic; poled optical superlattic;e was employed during the sum-frequency generation process.The optimized structure of the quasi-phase matching optical superlattic;e was studied by means of the genetic; algorithm.Femtosec;ond blue-light laser at 457nm c;an he generated through femtosec;ond pulse mixed with top-hat pump pulse in the aperiodic; optical superlattice.The simulation results indicate that this technique give a new scheme for generating a new ultrahort laser through nonlinear frequency conversion.