Photonic crystal all-fiber Interferometer for Temperature and Transverse Load Sensing based on phase demodulation

Abstract In this paper, a hybrid photonic crystal all-fiber sensor consisting of a fiber Mach–Zehnder interferometer (MZI) and a Fabry-Perot interferometer (FPI) was proposed and experimentally demonstrated, which spliced a section of photonic crystal fiber(PCF) between a microsphere cavity and single mode fiber (SMF) ball. Sensors' sensitivities to temperature and transverse load calculated through the phase shift were -0.032 rad/°C and -0.386 rad/N, which are more stable and accurate than conventional peak wavelength tracking due to the phase demodulation can avoid the effects of dip selection, wavelength sampling rate and spectral noise on the peak wavelength tracking.