A highly sensitive surface plasmon resonance (SPR) sensor composed of a photonic crystal fiber (PCF) with the D-type structure is designed and analyzed by the full-vector finite element method (FEM). Indium tin oxide (ITO) is adopted as the plasmonic substance on account of the low cost and controllable infrared range (1500–2600 nm). By optimizing the structural parameters, the sensor shows a maximum wavelength sensitivity of 46,000 nm/RIU and average sensitivity of 13,166.67 nm/RIU for analyte refractive indexes between 1.355 and 1.385. This PCF combining a circular layout and D-type structure offers excellent sensitivity while the deposition and manufacturing complexity can be reduced. This sensor will possess an extremely expansive development space in the field of chemical analysis and environmental safety.
Surface Plasmon Resonance Sensor Based on a Novel D-Shaped Photonic Crystal Fiber for Low Refractive Index Detection