CMOS compatible novel plasmonic refractive index sensor with high sensitivity based on alternative plasmonic material

A plasmonic refractive index (RI) sensor based on a highly doped silicon waveguide is proposed and investigated numerically. The RI sensor utilizes a heavily doped silicon waveguide instead of a conventional metal-insulator-metal (MIM) waveguide which makes it complementary metal-oxide-semiconductor (CMOS) compatible. A ring waveguide is coupled with the straight waveguide like MIM ring resonator structures and a similar resonance phenomenon is observed. The sensitivity is investigated and a sensitivity of 2150 nm/RIU is realized. The plasmonic sensor consists of a simple framework and uses only silicon waveguide and does not require any special material which makes it suitable for sensing systems in integrated optical circuits and also suitable for nanofabrication since it is CMOS compatible.