Optical sensing with antiresonant capillary fibers

Herein, we present a study of the use of polymer capillary optical fibers in sensing measurements. In particular, we approach the application of these fibers for temperature sensing. To do this, an analytical model for describing the spectral characteristics of the light transmitted through the capillaries was employed. Thermal expansion and thermo-optic effect influences on the transmitted spectrum were evaluated. Moreover, a 140 ± 6 pm/°C temperature sensitivity was measured, which is in good resemblance to simulated data and is around 14 times higher than the sensitivity attained in conventional Bragg gratings sensors.