Optical Gaussons in nonlinear directional couplers

This paper studies optical Gaussons in nonlinear directional couplers. Both twin-core couplers as well as multiple-core couplers are considered. For multiple-core couplers, coupling with nearest neighbors as well as coupling with all neighbors are considered. A closed form optical Gausson solution is obtained in all of these cases where the amplitude of the Gaussons is governed by a nonlinear difference equation. The domain restrictions naturally fall out as constraint conditions in order for the Gaussons to exist.