Superimposed multiple Bragg gratings

The authors demonstrate the inscription of seven Bragg gratings at the same location on a photosensitive fibre. These superimposed Bragg gratings were written over a 60 nm span in the region of 1530 nm with reflectivities better than 45%. Effects due to the inscription of multiple gratings within the same location on the fibre such as wavelength shifting and linewidth narrowing are studied.