Biosynthesized CuO nanoparticles–coated grating sensors for temperature measurement

In this study, we demonstrate temperature sensing using a fiber Bragg grating (FBG) fixed on a Teflon substrate with a large thermal expansion coefficient. A significant enhancement in sensitivity was achieved by coating the fiber with green synthesized copper oxide nanoparticles. This improvement was characterized by UV–visible spectroscopy, scanning electron microscopy, differential scanning calorimetry, and other techniques. The behavior of the coated materials is unique in their response to thermal stability based on the mode of coating. We have examined the thermal responses of FBG sensors mounted on temperature units on and after coating. The designed sensor is compact, cost effective, and measures temperatures in the range of 25 °C–200 °C. It demonstrated a linear relationship between the wavelength shift and temperature change along with 0.59 pm/ o C enhancement in the sensitivity. However, by optimizing the materials and physical dimensions of FBG, it is possible to increase the range of temperature detection, thereby improving the sensor’s performance. It is observed that the sensitivity of the nanoparticles-coated FBG is better than that of the bare FBG for all temperature ranges.