Strength of fusion splices for fibre lightguides

Fusion splices with median strengths in the range 2.1-2.8 GPa and coefficients of variation of about 40% have been obtained for synthetic fused silica fibre as well as for single mode and multimode lightguides using either flame, arc or laser heating. Although the strength distributions are broad, 90% of the splices have strengths above 1.4 GPa. These strengths, which are significantly higher than those previously reported, have been achieved by avoiding mechanical damage to the glass surface.