Surface plasmon resonance based fiber optic sensor with double resonance dips

A surface plasmon resonance based fiber optic sensor with bilayers of ITO–Au coated on the core of the optical fiber is presented and theoretically analyzed. The proposed sensor possesses high sensitivity with two resonance dips, one in the visible and other in the near infrared region of spectrum. With optimized values of thicknesses of ITO and Au layers to be 100 nm and 35 nm respectively, the highly sensitive SPR sensor has been shown to have 1929 nm/RIU and 929 nm/RIU sensitivities for left and right resonance dips respectively.