Ultrasensitive pressure sensor realized with two-semicircle hole fiber based on Sagnac interferometer

In this paper, we demonstrate a novel microstructure optical fiber designed for pressure measurement with ultrahigh sensitivity. The fiber has a cross-sectional structure of two-semicircle holes with a modal birefringence of -1×10
^-4
The demonstrated sensitivity of hydrostatic pressure is -44 nm/MPa, which is about 13 times higher than previously reported result.