Fabrication and optimisation of the erbium distribution in silica based doped fibres

The fabrication of erbium doped fibres is described in which the erbium is confined to the centre of the core using Al/sub 2/O/sub 3/-P/sub 2/O/sub 5/-SiO/sub 2/ host glass. The authors show that this distribution makes more efficient use of pump power. >