BS EN IEC 60793-2-50:2025 - Page 2

Optical fibres. Product specifications. Sectional specification for class B single-mode fibres | Status: Current

1 Scope This part of IEC 60793 is applicable to optical fibre categories B-652, B-653, B-654, B-655, B-656 and B-657. A map illustrating the connection of IEC designations to ITU-T designations is shown in Table 1. These fibres are used or can be incorporated in information transmission equipment and optical fibre cables. Three types of requirements apply to these fibres:

• • general requirements, as defined in IEC 60793‑2;
• • specific requirements common to the class B single-mode fibres covered in this document and which are given in Clause 4;
• • particular requirements applicable to individual fibre categories or specific applications, which are defined in Annex A to Annex F.

For some fibre categories (shown in the relevant family specifications), there are sub-categories that are distinguished on the basis of difference in transmission attribute specifications. The designations for these sub-categories are documented in the individual family specifications. Table 1 shows a map from the IEC designations to the ITU-T recommendations. The table also provides the normative annex in this document that contains the detailed specifications as well as the names used to describe these fibre types in IEC 60793‑2‑50:20151. The ITU-T recommendations as well as the IEC categories/sub-categories within each recommendation are given. In some cases, as for Recommendation G.652, a given IEC designation maps to multiple categories in the ITU-T because the ITU-T categories are distinguished by cabled fibre attribute (PMDQ) performance which are not distinguished in the IEC fibre specifications. Table 1 — Map of IEC designation to ITU-T Recommendations and IEC 60793‑2‑50:2015 designation Annex Category Sub category Description IEC 60793‑2‑50:2015 ITU-T Recommendation B-652 Dispersion unshifted fibre G.652 Annex A B-652.B B1.1 G.652.B Annex A B-652.D B1.3 G.652.D B-653 Dispersion shifted fibre G.653 Annex B B-653.A B2_a G.653.A Annex B B-653.B B2_b G.653.B B-654 Cut-off shifted fibre G.654 Annex C B-654.A B1.2_a G.654.A Annex C B-654.B B1.2_b G.654.B Annex C B-654.C B1.2_c G.654.C Annex C B-654.D N/A G.654.D Annex C B-654.E N/A G.654.E Annex D B-655 Non-zero dispersion shifted fibre B4 G.655 Annex D B-655.C B4_c G.655.C Annex D B-655.D B4_d G.655.D Annex D B-655.E B4_e G.655.E Annex E B-656 Wideband non-zero dispersion shifted fibre B5 G.656 Annex F B-657 Bending loss insensitive fibre B6 G.657 Annex F B-657.A1 B6_a1 G.657.A1 Annex F B-657.A2 B6_a2 G.657.A2 Annex F B-657.B2 B6_b2 G.657.B2 Annex F B-657.B3 B6_b3 G.657.B3