Bright and dark solitons in quadratic nonlinear periodic structures and application to an all-optical logic gate

By studying one-dimensional periodic structures with modulation of both linear and quadratic nonlinear susceptibilities, we obtain the stable propagation of a fundamental soliton pair with both bright and dark shapes and the stable propagation of a fundamental soliton series with bright shapes. Furthermore, we find that optical logic gate functions can be constructed by using these kinds of periodic structures and by setting different parameters. As examples, OR and XOR gates are presented