scope:

This technical report describes two methods for the measurement of the sensitivity of singlemode optical fibres to high-power damage at bends. - Method 1 - Failure time characterization as a function of the launch power and bend conditions (bend angle and bend diameter). - Method 2 - Equilibrium temperature measurement. Results from the two methods can only be compared qualitatively. The results, in this technical report, are predominantly on uncabled and unbuffered fibres. Cabled and buffered fibres are expected to respond differently - because the outer layers can affect the ageing process. Note also that Method 2 testing cannot be applied to buffered or cabled fibres. These methods do not constitute a routine test to be used in the evaluation of optical fibre. The parameters derived from the two methods are not intended to be specified within a detailed fibre specification. Note that the catastrophic failure modes arising and which are described in this technical report in general occur at bending radii much smaller than specified in the single-mode fibres specification, IEC 60793-2-50, or than would be recommended based on mechanical reliability considerations alone. The technical report includes Annex A which gives a discussion on the rationale for the approaches adopted, metrics for assessment, guidance, examples and some conclusions from initial studies.