Highly Sensitive Multi-coating Photonic Crystal Fiber Biosensor at Near-Infrared Waveband

A multi-coating photonic crystal fiber with a trapezoid-shaped slot (TS-PCF) for highly refractive index (RI) sensing is proposed. TiO2 and Indium tin oxide (ITO) are coated on the bottom of the polished-area, ITO is used as the plasmonic material. Through the full-vector finite element method (FV-FEM), the wavelength sensitivity of 5000~17000 nm/RIU in the analyte RI range of 1.31 to 1.36 is obtained. Moreover, the maximum amplitude sensitivity of 358.94 RIU^-1 is also achieved with the relevant resolution of 2.79E-5 RIU. The proposed fiber sensor can be the suitable candidate for real time detecting in medical diagnostics and biomolecules applications.