Scattering of a Beam Wave from a Dielectric Grating with Finite Extent

摘要

The scattering of a beam wave from the end-face of an ordered waveguide system with finite extent is treated by the perturbation method and the scattered wave is analytically derived. The scattered wave is composed of beam waves propagating along specific directions and the expressions of the beam waves are concretely given. When the extent of the waveguide system becomes infinite the expression of the scattered wave is that for an infinite system. The consistency of the far scattered field with that obtained by the saddle point method is discussed.