Silicon-compatible surface plasmon optical elements

Abstract

This invention provides fundamental science and novel device architectures for surface plasmon (SP)-based, complementary metal oxide semiconductor (CMOS)-compatible, optical elements such as modulators, couplers, and switches. The primary focus of the work is on waveguides based on an ultra-long-range surface plasmon (ULRSP) waveguide mode recently discovered by our team. This mode exists at the metal-dielectric interfaces in a silicon-oxide-metal-silicon layer structure. While initial work focuses on noble metals to support the ULRSP, our analysis shows Si processing-compatible metals such as Cu and Al can also be used. Our modeling has also shown that variation in the thickness of the oxide layer can be used to give unprecedented propagation lengths in such structures. Electrically-induced free carrier modulation of the dielectric constant in the Si adjacent to the oxide can modulate the waveguide properties allowing novel Si-compatible electro-optic devices to be created. These waveguides function as the 'wiring' in new classes of optical chips. This invention also provides integration of ULRSP waveguides and switches with other optical elements to create entirely new classes of hybrid optoelectronic technologies for defense applications. These range from chip-based chemical agent detection to extremely high performance processors and even all-optical computations.