Sensitivity enhancement of a wavelength interrogation-based optical fiber surface plasmon resonance sensor for hemoglobin concentration using barium titanate

In this paper, the performances of a wavelength interrogation-based optical fiber surface plasmon resonance sensor for hemoglobin (Hb) concentration is investigated by theoretical simulation. The proposed configuration incorporates optical fiber, 70 nm silver, 18 nm barium titanate (BaTiO 3 ), and 2 nm zinc oxide. Simulation results show the sensor exhibits refractive index sensitivity of 4023 nm/RIU and concentration sensitivity of 10.0873 nm/(g·dL), along with Hb concentration varying from 0 to 14 g/dL. This paper especially focuses on the influence of BaTiO 3 on the performances of the proposed sensor with light wavelength ranging from 350 to 1000 nm. Comparison analysis indicates sandwiching 18 nm BaTiO 3 between sensing layers not only enhances the concentration sensitivity by 30.14% but also decreases the nonlinear error of the sensor from 0.68% to 0.63%. For a wavelength accuracy of 0.1 nm, the proposed sensor can provide a resolution of 0.0099 g/dL for Hb concentration detection.