Benchmarking the response of Bragg gratings written in micro-structured and bow tie fiber embedded in composites

摘要

Fiber Bragg gratings written in Bow-tie fiber and in highly birefringent micro-structured optical fiber are embedded in a carbon fiber reinforced epoxy. The Bragg peak wavelength shifts are measured under controlled bending, transversal load and thermal cycling of the composite sample. The results evidence the feasibility of using micro-structured fibers in structural integrity monitoring. We obtain similar axial as well as transversal strain sensitivities for the two embedded fiber types. We also highlight an important advantage of the micro-structured fibers for this application which is the low temperature dependence of the birefringence.