Nonadiabatic Tapered Optical Fiber with GO/PVA Nanostructured Sensitive Coating for Humidity Sensing Application

A non-adiabatic tapered fiber sensor coated with humidity-sensitive graphene oxide (GO)/ Poly (vinyl) alcohol (PVA) nanocomposite film for humidity sensing application was proposed. GO/PVA film was deposited onto the tapered region by dip-coating technique. The surface morphology of the coating film was characterized through Field Emission Scanning Electron Microscope (FESEM). When exposed to percent relative humidity (RH) ranging from 20 to 99.9 % RH, the sensor exhibited sensitivity for both untapered and tapered fibers at -0.00132 +/- 0.00043 a. u (%)(-1) and 0.00106 +/- 0.00008 a. u (%)(-1), respectively. The contribution of GO/PVA composite film in enhancing sensor sensitivity was proven, which was 0.00624 +/- 0.00033 a. u (%)(-1) with percentage of sensitivity boosting up to 15.86 % when compare to the uncoated ones.