IEC 61744:2023 provides standard procedures for the calibration of optical fibre chromatic dispersion (CD) test sets. This document is applicable to all types of CD test sets, with the exception that measurements on multimode optical fibres are excluded. The purpose of this document is to define a standard procedure for calibrating optical fibre chromatic dispersion (CD) test sets. The detailed calibration steps used vary according to the measurement technique used in the CD test set. Whilst it is acknowledged that chromatic dispersion also occurs in multimode fibre and this fibre can be measured on many CD test sets, this document will restrict discussion to single mode fibre measurements applications only. The purpose of the procedures outlined in this document is to focus manufacturers and users of CD test sets toward the reduction of measurement uncertainty in chromatic dispersion determination in optical fibres under all applicable conditions. The procedures apply to calibration laboratories and to the manufacturers or users of CD test sets for the purpose of
a) calibrating CD test sets, and
b) evaluating the level of performance of the instrument.
Use of the procedures also allows correct evaluation of CD test set uncertainty, relative and traceable to appropriate (for example, national) standards. This third edition cancels and replaces the second edition published in 2005. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) updated terms and definitions;
b) the use of a reference fibre standard for calibration is now allowed and at the same level as the other calibration method;
c) Annex B was split into a new Annex B (on calibration uncertainty, still normative) and a new Annex C (on uncertainty at operating conditions, informative);
d) removed former C.3.4 on interferometric method since this method is no longer supported in IEC 60793-1-42;
e) removed Annex D and other references in text to calibration compensation to align with other calibration documents;
f) removed Annex E and other references in text to use of air wavelength since it is not used in the fibre domain.