Fabrication of Fiber Optic Based Temperature Sensor

Abstract The metal oxide semiconductors (ZnO, SnO 2 , Al 2 O 3 and TiO 2 ) were synthesized by co-precipitation method. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and UV-Visible spectrometer in diffused reflectance (DR) mode. The XRD results stipulated that the ZnO nanoparticle is crystallized in hexagonal wurtzite structure, SnO 2 nanoparticles in rutile tetragonal structure, Al 2 O 3 nanoparticle in rombohedral structure and TiO 2 nanoparticle in rutile anatase structure. The SEM investigation affirms that all the synthesized nanopowders are composed of uniformly distributed grains. The UV-Vis spectrum proclaimed that the synthesized nanoparticles having the band gap of 3.2 eV (ZnO), 3.3 eV (SnO 2 ) and 3.5 eV (TiO 2 ) respectively. The synthesized nanoparticles were replaced with small cladding region of the optical fiber and act as a temperature sensing materials. The temperature sensing characteristics of the synthesized nanoparticles were investigated for broad wavelength range (200-1000 nm). It reveals that the synthesized Al 2 O 3 nanoparticles were given linear and high sensitivity (∼27) at 697 nm compared with other sensing materials. Further, we have studied the wavelength dependent temperature sensing characteristics of Al 2 O 3 nanopowders and it show better sensitivity (∼34) in blue wavelength region (450 nm-495 nm).