Fabrication and thermal decay of fiber Bragg gratings in pristine and H 2 -loaded Bi-Al co-doped optical fibers

A cw-244-nm-Ar+ laser was used to fabricate Bragg gratings in pristine and H-2-loaded Bi-Al-SiO2 optical fibers with index changes as high as 3.6 x 10(-4) and 19.3 x 10(-4), respectively. For comparison, fiber Bragg gratings in pristine and H-2-loaded SMF-28e showed index changes of 13.6 x 10(-4) and 63.3 x 10(-4). Continuous isochronal thermal annealing revealed higher thermal stability for the H-2-loaded Bi-Al-SiO2 fiber compared to the pristine one. The SMF-28e fibers, with and without hydrogen, were more stable than the Bi-Al-SiO2 fibers. (C)2011 Optical Society of America