IEC 60793-2-50:2018

Overview

IEC 60793-2-50:2018 - Sectional specification for class B single‑mode fibres - defines product requirements for optical fibre categories B‑652, B‑653, B‑654, B‑655, B‑656 and B‑657. Applicable to optical fibres used in information transmission equipment and optical fibre cables, this sixth edition updates naming conventions, aligns with ITU‑T Recommendations and adds clarity on coating, dispersion and bending-loss‑insensitive fibre types.

Key topics and technical requirements

• Scope and mapping: Cross‑reference table links IEC designations to ITU‑T (G.652, G.653, G.654, G.655, G.656, G.657) to simplify global interoperability.
• Three tiers of requirements:
  • General requirements referenced from IEC 60793‑2.
  • Specific requirements common to class B single‑mode fibres (Clause 5): dimensional, mechanical, transmission and environmental attributes.
  • Particular requirements for individual categories and applications (Annexes A–F).
• Dimensional requirements: core, cladding and coating attributes and measurement methods.
• Mechanical requirements: tensile strength, strip force, stress‑corrosion susceptibility; test methods and limits common to class B fibres.
• Transmission requirements: attenuation, chromatic dispersion and related transmission attributes; sub‑category distinctions for differing transmission behavior.
• Environmental requirements: optical and mechanical environmental exposure tests, ageing (including hydrogen ageing for some sub‑categories).
• Category family annexes (A–F): detailed specifications for
  • B‑652 (dispersion‑unshifted),
  • B‑653 (dispersion‑shifted),
  • B‑654 (cut‑off shifted),
  • B‑655 (non‑zero dispersion‑shifted),
  • B‑656 (wideband non‑zero dispersion‑shifted),
  • B‑657 (bending‑loss insensitive).
• Edition 2018 technical updates:
  • Revised naming convention harmonized with ITU‑T.
  • Added details for 200 µm coated single‑mode fibre.
  • Harmonization with ITU‑T (Nov 2016) including revised chromatic dispersion specs, new categories and application spaces.
  • Annex titles updated to reflect fibre types.

Applications and users

IEC 60793‑2‑50:2018 is intended for:

• Fibre manufacturers specifying product acceptance criteria.
• Cable designers and integrators selecting fibres for optical fibre cables and information transmission equipment.
• Test laboratories and quality teams performing dimensional, mechanical, transmission and environmental testing.
• Network engineers and system designers choosing fibre types (e.g., bending‑insensitive B‑657 for tight‑space installations).
• Standards and procurement specialists requiring an IEC/ITU‑aligned specification for global projects.

Related standards

• IEC 60793‑2 (general requirements for optical fibres)
• ITU‑T Recommendations: G.652, G.653, G.654, G.655, G.656, G.657 (mapping and harmonization)

Keywords: IEC 60793‑2‑50:2018, optical fibres, single‑mode fibres, information transmission equipment, optical fibre cables, chromatic dispersion, bending loss, attenuation, fibre specifications.