Metal-coated CYTOP FBG: pressure sensing improvement

Recently, many researches have been conducted for enhancing the Fiber Bragg Grating (FBG) pressure sensitivity of sensors for different industrial application particularly those sensors for harsh environment sensing applications. In this paper, the FBG was used made of monomer (CYTOP) polymer fiber with selected certain parameters. Firstly, this sensor is coated with first layer of Pb nanoparticles Pb NPs and second thin layer of Ag. Secondly, a thin polymer patch was used to cover the FBG sensor. However, the results of the strain, temperature and pressure sensitivities were recorded using Optical Spectrum Analyzer (OSA); and the results were compared with bare silica FBG outcomes. Since FBG sensor is influence by temperature fluctuations, cascade FBGs technique was used. Different values of pressure were applied on FBG sensor leading to shifting in Bragg wavelength. Modified CYTOP FBG responded efficiently than bare silica FBG. The responsivity performance illustrates an enhancement in the pressure sensitivity values of the coated CYTOP FBG. Moreover, experimental results showed that the CYTOP FBG pressure sensor based on the metal coated achieved 120.35 pm/KPs for the pressure sensitivity with a 0.0002 kPa resolution precision. This result was compared with bare silica FBG sensitivity and performance and it was 2000 times higher. The proposed CYTOP FBG pressure sensor has the advantages of low production process and low cost; besides, it has the usage prospective within the field of harsh environment sensing applications.