We investigate a structure consisting of a magneto-optic multimode waveguid
e and two monomode waveguides serving as in- and outlets. Thc geometrical d
imensions of the multimode waveguide can be adjusted such that the guided m
odes interfere constructively in forward direction and destructively for ba
ckward propagation. In this paper we present concepts for a circulator and
two isolators based on multimode imaging.