Optical fiber refractive sensors enhanced by 2D hydrogen doped molybdenum oxide nanodisks

This paper has fabricated and characterized a bilayer SPR optical fiber sensor, enabled by hydrogen doped molybdenum oxide (HMO) nanodisks coated on the metal film's surface. Doped molybdenum oxide with ultra-doping and large permittivity properties can tune the plasmonic absorption in a visible region. The materials were synthesized by hydrothermal method, characterized by the atomic force microscope, Raman spectroscopy, and other analytical instruments. The electrical and optical properties of the materials are calculated and analyzed with density functional theory (DFT). The sensor measured the refractive index of a liquid solution, and a sensitivity of 2565 nm/RIU was achieved, which was approximately 1.4 times higher than that of a conventional SPR sensor without modification HMO nanodisks.