Optical Sensing Performance of Multimode Polymer Optical Fiber (POF) Coated with ZnO towards Methanol Vapour

In this work, optical sensing performance of multimode polymer optical fiber coated with ZnO towards methanol vapour with different concentrations is studied. The etching process of the POF was carried out using chemical etching method. ZnO was synthesized with sol-gel method to obtain the sensitive material coating. The etched optical fiber was then dip-coated with ZnO and dried at 70oC to enhance the binding of the materials and to remove organic residue. Scanning Electron Microscope (SEM), and X-Ray poer Difraction (XRD) analyses were performed to characterize the ZnO layer. The measurements of optical performance were taken using a spectrophotometer in the optical wavelength in the range of 500–8000nm. The absorbance response of the ZnO coated etched fiber reduced proportionally, upon exposure to methanol vapour with concentration in the range of 5%–50%.