Bragg gratings in carbon coated optical fibers and their potential sensor applications in harsh environment

摘要

We have demonstrated that fiber Bragg gratings can be written through the carbon layer of carbon-coated optical fibers having different coating thicknesses. Specifically, grating index modulation amplitudes of ～2.5×10~(-5) and 0.52×10~(-5) were obtained in optical fibers having carbon layers 29 run and 56 nm thick, respectively, without any extra photosensitization of the fibers. Subsequent experimental results showed that the carbon coatings in the grating areas didn't change their hermetic properties. Finally, we describe the advantages of these gratings and their potential applications in fiber optic sensing.