We report, for the first time to our knowledge, the excellent optical performance of long-period gratings written in three standard fibers and in two nonstandard fibers, namely, S-doped and N-doped fibers, using the flexible and low-cost electric arc technique. The fundamental mechanism for their formation is proposed. The gratings thermal behavior and the effect of fiber preannealing prior to writing have been investigated. We have demonstrated a good stability of these gratings at high temperatures.
G. Rego, O. Okhotnikov, E. Dianov, and V. Sulimov, "High-Temperature Stability of Long-Period Fiber Gratings Produced Using an Electric Arc," J. Lightwave Technol. 19, 1574- (2001)