DIFFRACTION FROM CONCAVE GRATINGS IN PLANAR WAVE-GUIDES

Performance of planar waveguide devices employing concave gratings can be numerically modeled with diffraction theory. The details of the me thod are presented, Approximations are introduced to derive simple equ ations and numerical calculations are:used to verify the approximation s. These formulas clarify the sources of loss caused by concave gratin gs and their application for optimizing grating performance is demonst rated.