The mechanism for inscription of electric-arc-induced long-period gratings in SMF28 fiber was studied. The refractive-index profiles of irradiated fiber samples were measured, and their structures were investigated by Raman and luminescence spectroscopy. Slight geometrical deformations of the irradiated fiber were measured. A significant change in the Raman spectrum range from 200 to 700 cm<sup>−1</sup> caused by the electric arc is reported. The results show a decrease in the intensity of this band, indicating a modification, such as densification, of the glass structure. No modification of the fictive temperature was measured. A large increase in the red luminescence band was also observed and attests to the creation of defects in the fiber network structure.
© 2003 Optical Society of America
Abdelrafik Malki, Georges Humbert, Youcef Ouerdane, Aziz Boukhenter, and Azzedine Boudrioua, "Investigation of the Writing Mechanism of Electric-Arc-Induced Long-Period Fiber Gratings," Appl. Opt. 42, 3776-3779 (2003)