Multiplexing of anti-resonant reflecting optical waveguides for temperature sensing based on quartz capillary

A novel multiplexing scheme of anti-resonant reflecting optical waveguides (ARROW) for temperature sensing based on quartz capillary is firstly proposed and experimentally demonstrated. Each ARROW-based sensor is manufactured by fusion splicing a short section of capillary between two standard single-mode fiber (SMF). Experiments were demonstrated on a three cascaded ARROW-based sensing network chopped from a fiber array with multiple sensors. Simulation and experimental results demonstrate that the positions of sharp periodic transmission dips are independent of the capillary length, but dependent on the refractive indexes and thickness of the silica cladding. The temperature sensitivities of 18.77 pm/°C, 18.19 pm/°C, and 17.94 pm/°C are achieved by wavelength demodulation of selected dips of Gaussian fitting algorithm, and the tunability of sensitivity can be realized by selecting different dips. Furthermore, the merits of low strain cross-sensitivity (-0.71 pm/με), easy fabrication capability and high spectral extinction ratio (about 30dB) make the proposed multiplexing scheme an excellent candidate for performing multi-point and multi-parameter measurements in harsh environments.