Humidity and temperature sensor based on pokal-taper and lateral-offset structure

An interferometric optical fiber sensor based on pokal-taper structure and lateral-offset structure is proposed. In order to increase the humidity sensitivity of the sensor, the sensing area is coated with 1mg/ml concentration of graphene dispersion. The temperature sensitivities are 0.097nm/°C and 0.127nm/°C in the temperature range of 0°C~40°C. The humidity sensitivities are 0.039nm/%RH and 0.042nm/%RH in the humidity range of 30%~70%. With some advantages of small size, anti-electromagnetic interference, the proposed sensor has broad application prospects.