Surface plasmon resonance sensor based on symmetrical side-polished dual-core photonic crystal fiber

Abstract

• Symmetrical polishing structure of dual-core photonic crystal fiber. • Gold layer is plated on the symmetrical side-polished surface of PCF to excite the surface plasmon polaritons. • The proposed sensor is able to detect the analyte the refractive indexes in the range of 1.3–1.42. • The maximum sensitivity of the proposed sensor is 8000 nm/RIU. A surface plasmon resonance (SPR) sensor based on symmetrical side-polished dual-core photonic crystal fiber (DC-PCF) with a wide refractive index (RI) detection is proposed and analyzed. A gold layer is placed on the symmetrical side-polished surface of photonic crystal fiber to excite the surface plasmon polaritons (SPPs). The proposed DC-PCF consists of the symmetrical air-holes and symmetrical side-polished structure. The design without air holes on both sides of the core can efficiently realize phase matching between the core guided mode and the plasma mode. Numerical simulation results show a maximum sensitivity as high as 8000 nm/RIU (refractive index unit) with a resolution of 1.3 × 10 −5 RIU. It has a significant advantage in the field of chemical and biological detection because it is able to detect the analyte RI in the range of 1.3–1.42.