Interferometric temperature sensor based on a water-filled suspended-core fiber

The performance of water-filled suspended-core fibers as key components of interferometric temperature sensors has been analyzed. Use of water is motivated by simplicity of use and by its thermo-optic and thermal expansion coefficients, which provide a good balance between sensitivity and wide temperature range (limited by the free spectral range of the interferometer). Two suspended core fibers have been tested. With one of them, the sensitivity observed is slightly better than the ones of most interferometers based on liquid-filled photonic crystal fibers, with a linear temperature range of 25ºC. With regard to the other one, its most remarkable feature is its temperature range, not limited by any interferometric property but by water melting and boiling temperatures, as its quotient between free spectral range and sensitivity is higher than 100ºC