The effect of the TiO2 film on the performance of the optical fiber SPR sensor

We studied the effect of the Titanium Oxide (TiO2) film on the performance of the optical fiber SPR with two kinds of probes. The light guiding properties and sensing performance of the D-type optical fiber SPR sensor coated with TiO2 was studied numerically by finite element method (FEM) and the sensing performance of the multimode-single mode-multimode (MSM) hetero-core optical fiber SPR sensor coated with TiO2 was investigated experimentally. The simulation and experimental results for two kinds of probes consistently show that the absence of TiO2 film layer on the gold film can enhance the refractive index sensitivity and tune the resonance curve of the sensor from visible light to near-infrared.