| Abstract: | The present invention relates to optical vias to optically connect
multilevel optical circuits. In one example, the optical via includes a
surface plasmon polariton waveguide, and a first optical waveguide formed
on a first substrate is coupled to a second optical waveguide formed on a
second substrate by the surface plasmon polariton waveguide. In some
embodiments, the first optical waveguide includes a transition region
configured to convert light from an optical mode to a surface plasmon
polariton mode or from a surface plasmon polariton mode to an optical
mode. |