In this work, two all-fibre interferometric configurations based on suspended core fibres (SCF) are
investigated. A Fabry-Pérot cavity made of SCF spliced in-between segments of single-mode and hollow-core
fiber is proposed. An alternative sensing head configuration formed by the insertion of a length of
SCF as a birefringence element in a Sagnac interferometer is also demonstrated. The sensitivity to pressure
and temperature was determined for both configurations.
In this work, sensitivity to strain, temperature and curvature of a sensor relying on modal interferometry in hollow-core
photonic crystal fibre is studied. The sensing structure is simply a piece of hollow-core fibre connected in both ends to
standard single mode fibre. An interference pattern that is associated to the interference of the light that propagates in
the hollow core fundamental mode with light that propagates in other modes is observed. The phase of this interference
pattern changes with the measurand interaction, which is the basis for considering this structure for sensing. The phase
recovery is performed using a white light interferometric technique.
In this work, interferometric sensors based on antiresonance reflecting waveguide (ARROW) fibers were developed and
their performances were characterized for measurement of physical parameters, particularly strain and temperature. Two
types of ARROW fibers were considered and signal demodulation was achieved using the white light interferometric
technique. Application issues of sensing heads based on these fibers are also addressed.
In this article, we propose a simple method to increase the pressure sensitivity of a typical fiber Bragg grating (FBG) while decreasing the temperature sensitivity. This method uses a typical FBG, which is coated with a thick layer of polymer with two symmetric air channels. By this method the pressure sensitivity can be increased (e.g. 1.1×10<sup>-5</sup> /MPa) while the temperature sensitivity is negligible (e.g. -0.174×10<sup>-8</sup>/<sup>o</sup>C) by proper selection of the geometrical parameters and material types of the sensor.