title: Intermodal interferometer for strain and temperature sensing fabricated in birefringent boron doped microstructured fiber.
abstract: We present a compact in-line fiber interferometric sensor fabricated in a boron doped two-mode highly birefringent microstructured fiber using a CO(2) laser. The intermodal interference arises at the fiber output due to coupling between the fundamental and the first order modes occurring at two fiber tapers distant by a few millimeters. The visibility of intermodal interference fringes is modulated by a polarimetric differential signal and varies in response to measurand changes. The proposed interferometer was tested for measurements of the strain and temperature, respectively, in the range of 20-700 °C and 0-17 mstrain. The sensitivity coefficients corresponding to fringe displacement and contrast variations are equal respectively for strain -2.51 nm/mstrain and -0.0256 1/mstrain and for temperature 16.7 pm/°C and 5.74×10(-5) 1/°C. This allows for simultaneous measurements of the two parameters by interrogation of the visibility and the displacement of interference fringes.
authors.affiliation: Wroclaw University of Technology, Institute of Physics, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland. Gabriela.Statkiewicz@pwr.wroc.pl
authors.forename: G
authors.initials: G
authors.lastname: Statkiewicz-Barabach
authors.forename: J P
authors.initials: JP
authors.lastname: Carvalho
authors.forename: O
authors.initials: O
authors.lastname: Frazão
authors.forename: J
authors.initials: J
authors.lastname: Olszewski
authors.forename: P
authors.initials: P
authors.lastname: Mergo
authors.forename: J L
authors.initials: JL
authors.lastname: Santos
authors.forename: W
authors.initials: W
authors.lastname: Urbanczyk