Properties of sandwich-structure based Mach-Zehnder interferometer cascaded with FBG response to dual- parameter sensing

Abstract:

An all-fiber temperature and curvature sensor based on Mach-Zehnder interferometer (MZI) was proposed. The MZI was a sandwich structure which is composed of ring-core fiber (RCF), no-core fiber (NCF) and single-mode fiber (SMF). The temperature and curvature can be demodulated by the wavelength shift and the intensity variation of the dips respectively in the transmission spectrum. The measurement results show that the sensitivity of curvature is −7.88 dBm/m-1 in the range from 3.0 m-1 to 4.2 m-1 and the sensitivity of temperature is 53.5 pm/°C in the range from 60 °C to 200 °C. In addition, the cascaded FBG in the proposed structure, also sensitive to temperature, was used to monitor the fluctuation of temperature. The compact structure, the real-time temperature and the high curvature sensitivity make the sensor have the potential in the field of construction health monitoring and mining safety production.