Humidity and temperature sensor based on GOQDs-PVA coated tapered no-core fiber combined with FBG

A simple structure optical fiber sensor for relative humidity (RH) and temperature measurement is proposed and verified in this paper, which is based on graphene oxide quantum dots and polyvinyl alcohol (GOQDs-PVA) composite coated tapered no-core fiber (NCF) combined with a fiber Bragg grating (FBG). FBG is insensitive to humidity and sensitive to temperature, which is used to compensate temperature of the sensor. Experimental results show this sensor has humidity sensitivity of 143.27 pm/%RH ranging from 30%RH to 80%RH and the temperature sensitivity of 9.21 pm/°C. The proposed sensor has advantages of simple structure, good repeatability, and good stability, which is expected to be used in both RH and temperature measurement in biological and chemical fields.