Research on NCF-PCF-NCF Structure Interference Characteristic for Temperature and Relative Humidity Measurement

A novel structure of photonic crystal fiber (PCF) Mach-Zehnder interferometer (MZI) for temperature and relative humidity measurement is proposed. The novel structure is composed of two sections of no core fiber (NCF) with a piece of PCF. The sensitivity of the proposed sensor is enhanced by adopting NCF coupling method. The results show that the sensitivities of temperature are 0.059 nm/°C, 0.074 nm/°C and 0.130 nm/°C in the range of 25 °C to 70 °C, and the sensitivities of relative humidity are 0.020 nm/%RH, 0.027 nm/%RH and 0.036 nm/%RH in the range of 30%RH to 70%RH. The sensor has the advantages of high stability, good linearity fit and simple structure, which indicates that the sensor has the potential of making an important contribution to the field of biology, chemistry, and medical.