title: Titanium dioxide nanoparticle based optical fiber humidity sensor with linear response and enhanced sensitivity.
abstract: An optical fiber humidity sensor employing an in-house scaled TiO2-nanoparticle doped nanostructured thin film as the fiber sensing cladding and evanescent wave absorption is reported. The main objective of the present work is to achieve a throughout-linear sensor response with high sensitivity, possibly over a wide dynamic range using the simplest possible sensor geometry. In order to realize this, first, the nanostructured sensing film is synthesized over a short length of a centrally decladded straight and uniform optical fiber and then a comprehensive experimental investigation is carried out to optimize the design configuration/parameters of the nanostructured sensing film and to achieve the best possible sensor response. Much improved sensitivity of 27.1 mV/%RH is observed for the optimized sensor along with a throughout-linear sensor response over a dynamic range as wide as 24% to 95%RH with an average response time of 0.01 s for humidification and 0.06 s for desiccation. In addition, the sensor exhibits a very good degree of reversibility and repeatability.
authors.affiliation: Department of Physics, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.
authors.forename: R
authors.initials: R
authors.lastname: Aneesh
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Khijwania
mesh_terms: D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D006813:Humidity; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission / Q000379:methods; D049329:Nanostructures; D036103:Nanotechnology / Q000379:methods*; D055100:Optical Fibers; D055095:Optics and Photonics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
chemical_list: C009495:titanium dioxide; D014025:Titanium