Barium titanate film based fiber optic surface plasmon sensor with high sensitivity

An optical fiber/Au film/barium titanate (BaTiO3) thin film surface plasmon resonance (SPR) sensor is proposed. Improving sensitivity by charge transfer between Au and BaTiO3. The calculation of transfer matrix method shows that BaTiO3 are coated on the surface of the sensing area, the simulation sensitivity of the sensor reaches 2820 nm/RIU. The finite element method simulation shows that BaTiO3 can improve the electric field intensity in the sensing region. The experimental results of refractive index show that the sensitivity of optical fiber/Au film/BaTiO3 film SPR sensor is 2543 nm/RIU in the low refractive index range, 495 nm/RIU higher than that of traditional Au film SPR sensor. In the high refractive index range, the sensitivity of the sensor can reach 6040 nm/RIU. The sensor has broad application prospects in the field of biosensor.