Highly birefringent microstructured optical fiber for distributed hydrostatic pressure sensing with sub-bar resolution

We demonstrate distributed optical fiber-based pressure measurements with subbar pressure resolution and 1 m spatial resolution over a similar to 100 m distance using a phase-sensitive optical time-domain reflectometry technique. To do so, we have designed a novel highly birefringent microstructured optical fiber that features a high pressure to temperature sensitivity ratio, a high birefringence and a mode field diameter that is comparable to that of conventional step-index single mode fibers. Our experiments with two fibers fabricated according to the design confirm the high polarimetric pressure sensitivities (-62.4 radxMPa(-1)xm(-1) and -40.1 radxMPa(-1)xm(-1)) and simultaneously low polarimetric temperature sensitivities (0.09 radxK(-1)xm(-1) and 0.2 radxK(-1)xm(-1)), at a wavelength of 1550 nm. The fiber features a sufficiently uniform birefringence over its entire length (2.17x10(-4) +/- 7.65x10(-6)) and low propagation loss (similar to 3 dB/km), which allows envisaging pressure measurements along distances up to several kilometers. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

We demonstrate distributed optical fiber-based pressure measurements with subbar pressure resolution and 1 m spatial resolution over a similar to 100 m distance using a phase-sensitive optical time-domain reflectometry technique. The high birefringence microstructured optical fiber designed in this study exhibits high polarimetric pressure sensitivities and low polarimetric temperature sensitivities at a wavelength of 1550 nm. The uniform birefringence and low propagation loss of the fiber enable pressure measurements along distances up to several kilometers.