Generalization of the coordinate transformation method with application tosurface-relief gratings

The coordinate-transformation-based differential method, initially used by Chandezon et al. for modeling surface-relief gratings, is now known as a po werful rigorous formalism for solving diffraction problems. We explain a co ordinate transformation that generalizes the original one, and we extend th e formulation to a wide class of monodimensional surface shapes. The bounda ry-value problem turns on the same eigenvalue problem for the TE and TM pol arizations. (C) 1999 Optical Society of America [S0740-3232(99)03703-5].