Until now, the theory has been general—whether the mesh was inductive or capacitive has not been specified. Since τ τ ( ω ω ) and Γ Γ ( ω ω ) are independent of polarization, we can apply Babinet's principle to the capacitive and inductive grids. Babinet's principle states that if we swap the metallic parts of a grid for the gaps, (i.e., make a complementary mesh), then the sum of the transmitted wave from the original structure and the structure's complement must equal the original incident wave. Therefore, if we have complementary capacitive and inductive grids,