An apparatus and method for splitting and combining optical beams with reduced
contact loss and electrical isolation. In one embodiment, an apparatus according
to embodiments of the present invention includes a first optical waveguide section
disposed in semiconductor material. The apparatus further includes second and third
optical waveguide sections symmetrically disposed in the semiconductor material
proximate to an end of the first optical waveguide section. First and second insulating
gap regions are disposed in the semiconductor material between the first and second
optical waveguide sections and the first and third optical waveguide sections,
respectively, such that there is a first evanescent coupling between first and
second optical waveguide sections across the first insulating gap region and there
is a second evanescent coupling between the first and third optical waveguide sections
across the second insulating gap region. The first, second, and third waveguide
sections are electrically isolated.