Efficient directional coupling between silicon and copper plasmonic nanoslot waveguides: toward metal-oxide-silicon nanophotonics.

Coupling plasmonics and silicon photonics is the best way to bridge the size gap between macroscopic optics and nanodevices in general and especially nanoelectronic devices. We report on the realization of key blocks for future plasmonic planar integrated optics, nano-optical couplers, and nanoslot waveguides that are compatible both with the silicon photonics and the CMOS microelectronics. Copper-based devices provide for very efficient optical coupling, unexpectedly low propagation losses and a broadband sub-50 nm optical confinement. The fabrication in a standard frontline microelectronic facilities hints broad possibilities of hybrid opto-electronic very large scale integration.