Simple fusion splicing technique for reducing splicing loss between standard singlemode fibres and erbium-doped fibre

A simple and practical splicing technique based on the diffusion of core dopant for reducing the coupling loss between standard singlemode fibre and small-core high numerical aperture (NA) erbium-doped fibre using a commercial arc fusion splicer is outlined. Results of coupling between a standard singlemode fibre and an erbium-doped fibre with a core radius of 1.85 mu m is presented. Using this technique, an excess loss of less than 0.1 dB was obtained consistently. This represents a significant reduction of splice loss, by about 1.8 dB over the conventional splicing method.