Grating-assisted backward coupling between two parallel waveguides is analyzed with a set of four coupled equations. The equations were recently derived by a unified approach that is appropriate for other coupling problems as well. Examples include three different operation regions and provide for the field variation along the guides as well as for the reflectivity and transmission coefficients. It is shown that the reduction of the four-wave coupling problem to a set of two coupled equations is possible only for some specific cases and at the cost of reduced accuracy. The model may be especially useful for the design of optical components for various applications such as optical switching and multiplexing.
© 1999 Optical Society of America
(050.1950) Diffraction and gratings : Diffraction gratings
(050.2770) Diffraction and gratings : Gratings
(130.2790) Integrated optics : Guided waves
(230.7390) Optical devices : Waveguides, planar
Nahum Izhaky and Amos Hardy, "Analysis of grating-assisted backward coupling employing the unified coupled-mode formalism," J. Opt. Soc. Am. A 16, 1303-1311 (1999)