Abstract

The coupled mode theory has been very useful in studying integrated optics devices including electrooptical couplers, semiconductor laser arrays, and optical wavelength filters. It has been demonstrated recently that the conventional coupled mode theory may violate energy conservation and the reciprocity theorem as much as 55% for strongly coupled waveguides.^1,2 A variational approach for the coupled mode theory has been used by Haus et al., for a lossless system. A generalized reciprocity theorem has also been applied to derive the coupled mode equations for a coupled waveguide system which can be lossy or lossless.² The results have also been shown to be identical to those of the variational approach for a general lossy or lossless medium.²

© 1986 Optical Society of America