Stable propagation and all-optical switching in planar waveguide-antiwaveguide periodic structures

A planar periodic nonlinear structure composed of alternating waveguiding (WG) and antiwaveguiding (AWG) sections is considered, Detailed simulations demonstrate that fairly long stable propagation of a beam in this structure is achieved when the lengths of the AWG and WG sections are equal, i.e., both ∼25 wavelengths. Another interesting result is that the stable-propagation length is much larger in both a uniform AWG and in the alternate structure if the input has a Gaussian transverse profile rather than a specially prepared shape that corresponds to the eigenmode of the (anti)waveguide. It is demonstrated that an efficient all-optical switching scheme, controlled by a weak hot spot, which is created by a laser beam shone normally to the structure and focused off axis near the end of any AWG section, can readily be realized in the alternate waveguide.