BRAGG GRATINGS IN CE-3+-DOPED FIBERS WRITTEN BY A SINGLE EXCIMER PULSE

Gratings with as high as 2.4% reflection efficiency written by a 20-ns single excimer pulse at 248 nm have been demonstrated for the first time to our knowledge in Ce3+-doped fibers. The grating strength is shown to increase with Ce3+ concentration under the same writing conditions. Investigation of the grating decay at elevated temperatures has revealed several different time constants, showing that several different types of mechanism may be involved. Part of the grating was found to be stable for > 10 h at 600-degrees-C.