The present invention provides an optical waveguide modulator. In one
embodiment, the optical waveguide modulator includes a semiconductor
planar optical waveguide core and doped semiconductor connecting paths
located adjacent opposite sides of the core and capable of applying a
voltage across the core. The optical waveguide core and connecting paths
form a structure having back-to-back PN semiconductor junctions. In
another embodiment, the optical waveguide modulator includes a
semiconductor optical waveguide core including a ridge portion wherein
the ridge portion has at least one PN semiconductor junction located
therein. The optical waveguide modulator also includes one or more doped
semiconductor connecting paths located laterally adjacent the ridge
portion and capable of applying a voltage to the ridge portion.