Applications of optical fibers in telecommunication and sensing were rapidly emerging where the fiber properties were related to the controlled addition of dopants such as Ge, P, F and Er. The modern ToF-SIMS instrument, with its high sensitivity and high lateral resolution, had shown to be an excellent tool to directly analyze cross-sections of as-manufactured fibers. The present work describes ToF-SIMS imaging of the dopant distribution in F-, Ge- and rare-earth-doped fibers where dopants were confined to a few μm in the core. The increased F diffusion in the F-doped fibers due to chemical reactions with hydroxyl groups was examined. This process was utilized in the manufacture of thermally stable chemical composition fiber Bragg gratings. It was possible to produce

ToF-SIMS elemental images with a lateral resolution around 0.5μm showing the detailed distribution of the dopants.

ToF-SIMS Imaging of Dopant Diffusion in Optical Fibers. M.Hellsing, M.Fokine, Å.Claesson, L.E.Nilsson, W.Margulis: Applied Surface Science, 2003, 203-204, 648-51