Diffraction from concave gratings in planar waveguides

Abstract

Performance of planar waveguide devices employing concave gratings can be numerically modeled with diffraction theory. The details of the method are presented. Approximations are introduced to derive simple equations and numerical calculations are used to verify the approximations. These formulas clarify the sources of loss caused by concave gratings and their application for optimizing grating performance is demonstrated.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>