This part of IEC 60793 establishes uniform requirements for measuring the cut-off wavelength of single-mode optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes.
This standard provides methods for measuring the cut-off wavelength of cable, fibre, and jumper cable.
Two methods exist for measuring cable cut-off wavelength, λcc:
- method A: using uncabled fibre;
- method B: using cabled fibre.
There is only one method for measuring fibre cut-off wavelength, λc.
There is only one method for measuring jumper cable fibre cut-off wavelength, λcj.
The test method in this standard describes procedures for determining the cut-off wavelength of a sample fibre in either an uncabled condition (λc) or in a cable (λcc) or as a jumper cable (λcj). Three default configurations are given here: any different configuration will be given in a detail specification. This method applies to all B fibre types.
All methods require a reference measurement. There are two reference-scan techniques, either or both of which may be used with all methods:
- bend-reference technique;
- multimode-reference technique.