Humidity sensor based on core-offset fiber Mach-Zehnder interferometer coated graphene oxide film

Recently, some fiber sensing applications by coating graphene oxide or reduce graphene oxide have been proposed. In this paper, a novel humidity sensor based on core-offset fiber Mach-Zehnder interferometer coated graphene oxide film has been carried out. Here, we use the chemical method to deal with the surface of the fiber first, and then coated graphene oxide on the surface of the optical fiber sensing arm. The sensitivity of 0.104dB/%RH with a linear correlation coefficient of 99.61% and good stability under the relative humidity range of 30%–60% was obtained.