This standard BS EN 60793-1-61:2017 Optical fibres is classified in these ICS categories:
33.180.10 Fibres and cables
This part of IEC 60793 establishes uniform requirements for measuring the polarization crosstalk of polarization-maintaining (PM) fibres.
This document gives two methods for measuring the polarization crosstalk of PM fibres. Method A is the power ratio method, which uses the maximum and minimum values of output power at a specified wavelength, and Method B is the in-line method, which uses an analysis of the Poincaré sphere.
Details of each method are described in Clause 6.
Crosstalk values obtained by Methods A and B are based on different definitions.
The crosstalk measured by Method A is defined as an "averaged" value over a measured wavelength range. In contrast, the crosstalk value obtained from Method B shows the "worst case" crosstalk value.