Splicing tolerances in graded-index fibres

Calculations are presented showing that, in general, a parabolic-index fiber is more sensitive to lateral misalignments within a splice than a step-index fiber. However, misalignments result in the excitation of leaky modes in graded-index fibers, and this can lead to optimistic joint loss measurements. Effective losses are given for various lengths of fiber following the splice, and it is shown that a parabolic-index fiber may appear more tolerant to misalignment than a step-index fiber when short lengths are used