A succession of directional couplers, which differ only through their refra
ctive index distribution, is shown to be the optical analog of type II semi
conductor heterostructures. The design of such a dielectric structure with
the same transmission characteristic of the electric field propagating thro
ugh it as the electron wave function in a type II heterostructure is discus
sed. An example of the design procedure is also given. (C) 2000 American In
stitute of Physics.[S0021-8979(00)06813-4].