Ray-optical determination of strong backward coupling coefficients of waveguide gratings by use of the rigorous coupled-wave theory

摘要

For the calculation of the backward coupling coefficients of grating waveguide devices the rigorous ray-optics method (RROM) based on the rigorous coupled-wave theory (RCWT) is more rigorous than the other conventional methods of ray-optics and coupled modes. The RROM proposed can be applied to diffractive waveguide devices even with arbitrary grating shapes as well as with arbitrary coupling strength.