Ying-Jie Luo, Shao-Yi Wu, Qin-Sheng Zhu, Xiao-Yu Li, Yong-Xin Li, De-Shuang Zhao
March 3, 2021
Previous studies of the gold-nanoparticles-covered U-type medical optical fiber sensor with millimeter size were mainly confined to the experimental aspect, while the corresponding theoretical studies were only for bare fibers based on geometrical optics or those for micron level photonic crystal fibers based on wave optics. Combining wave and geometrical optics, the gold-nanoparticles-covered U-type optical fiber sensor was simulated with millimeter size. The localized surface plasmon resonance absorption peak near 540 nm is obtained in the simulation, very close to that (≈560 nm) of the experimental value for the gold nanoparticles of 37 nm size. Compared with the refractive index (RI) sensitivity (≈7.10/RIU) for the plain, U-type optical fiber (≈43.50/RIU) exhibits more than 610% enhancement in the gold-nanoparticles-covered sample. Present studies would be helpful to the further simulation and design for various noble metal nanoparticles covered optical fiber sensors with different shapes.