Diffraction by a dielectric wedge with the neumann expansion of correction currents on interfaces

A new representation of fringe currents, which corrects the physical optics approximation for edge diffraction by a dielectric wedge, is obtained. In comparison with the multipole expansion at an edge, the proposed Neumann expansion of correction currents along the dielectric interfaces satisfies the edge condition at the edge and provides fast convergence after finite truncation of expansion coefficients.