Characterization of plain and ZnO coated D-shaped plastic optical fiber sensor of different diameters

The sensitivity and simple fabrication of fiber sensor are major concerns now a days. In this work, the effect of sensor diameter and zinc oxide (ZnO) sensing layer on the intensity of D-shaped multimode plastic optical fiber (POF) sensor was experimentally investigated. A simple side polishing method was used to prepare a fiber sensor of various diameters having a length of 30 cm. The sensor is coated with ZnO using hydrothermal method. The behavior of both plain and coated fiber sensor in terms of intensity were recorded using spectrometer. After analysis, it was observed that plain and coated sensor having a diameter of 500 generated strong evanescent waves, which resulted in a lower intensity and higher absorbance. The proposed method is efficacious for improving the sensitivity of optical fiber sensors.