IEC 61755-6-2-2018 PDF

Full title and description

Fibre optic interconnecting devices and passive components - Connector optical interfaces - Part 6-2: Connection of 50 μm core diameter multimode physically contacting fibres - Non-angled for reference connector application, at wavelength of 850 nm using selected A1a fibre only. This part defines the dimensional limits and optical-interface requirements for non‑angled, physically contacting multimode reference connectors intended for attenuation measurement and reference-connection applications.

Abstract

IEC 61755-6-2:2018 specifies geometry, tolerances and performance criteria for a single grade of non‑angled multimode reference connector (50 µm core) used with selected IEC 60793-2-10 A1a fibre at 850 nm to minimise variability in fibre‑to‑fibre attenuation measurements performed in factory or field environments. The standard includes criteria for fit to the performance grade, description of a reference adapter and considerations on measurement uncertainty.

General information

• Status: Replaced / cancelled by later IEC 63267 series (technical revision).
• Publication date: 21 June 2018 (IEC publication date).
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 33.180.20 (Fibre optic interconnecting devices).
• Edition / version: Edition 1.0 (2018).
• Number of pages: 25 (IEC webstore listing).

Scope

The standard applies to reference connectors with cylindrical ferrules that connect 50 μm core diameter multimode, non‑angled, physically contacting fibres at 850 nm using selected IEC 60793‑2‑10 A1a fibre only. It defines dimensional limits and tolerances, a single performance grade for reference connectors, requirements for reference adapters and guidance on the contribution of the reference connection to attenuation measurement uncertainty in factory and field conditions.

Key topics and requirements

• Dimensional limits and geometric tolerances for the optical interface of reference connectors (cylindrical ferrule geometry).
• Definition of one performance grade for non‑angled PC multimode reference connectors to limit measured attenuation variation.
• Mandatory use of selected IEC 60793‑2‑10 A1a multimode fibre for the reference connector design and verification.
• Criteria and tests to demonstrate a connector meets the performance grade (fit criteria, calculated random‑mated attenuation).
• Reference adapter description and guidance on how the reference connector contributes to overall attenuation measurement uncertainty (informative annex on multimode attenuation measurement uncertainty).

Typical use and users

Used by connector and ferrule manufacturers, test and calibration laboratories, installers and field technicians performing attenuation verification, and standards committees for connector/interface definition. Typical applications are calibration of test reference plugs, factory and field attenuation measurements, and procurement specifications for reference connectors.

Related standards

Closely related references and series include IEC 61755 (connector optical interfaces series), IEC 60793‑2‑10 (multimode fibre categories A1a), and IEC 61300‑3‑4 (attenuation examination and measurement procedures). IEC 61755-6-2:2018 has been technically superseded by the IEC 63267 family (notably IEC 63267‑2‑2:2024 and IEC 63267‑3‑61:2025) which update reference connector parameters for enhanced macrobend multimode fibres and define new reference grades and expanded fibre categories.

Keywords

fibre optic, connector optical interface, reference connector, multimode, 50 µm, 850 nm, A1a, physical contact (PC), attenuation measurement, reference adapter.

FAQ

Q: What is this standard?

A: IEC 61755-6-2:2018 is an IEC international standard that defines the dimensional and optical-interface requirements for non‑angled, physically contacting 50 µm multimode reference connectors used at 850 nm with selected A1a fibre for attenuation reference applications.

Q: What does it cover?

A: It covers geometry and tolerance limits, a single performance grade for reference connectors, criteria for fit to that grade, reference adapter description and the reference connection's contribution to attenuation measurement uncertainty when used with selected A1a multimode fibre.

Q: Who typically uses it?

A: Connector and ferrule manufacturers, test and calibration laboratories, field technicians performing attenuation tests, procurement/specification authors, and standards developers concerned with consistent fibre‑to‑fibre attenuation reference connections.

Q: Is it current or superseded?

A: IEC 61755-6-2:2018 has been cancelled and replaced by updated IEC documents in the IEC 63267 series (for example IEC 63267‑2‑2:2024 and IEC 63267‑3‑61:2025). The IEC 63267 publications constitute a technical revision with new reference grades and updated fibre categories. Users should refer to the IEC 63267 parts for the current requirements.

Q: Is it part of a series?

A: Yes — it is part of the connector optical interfaces standards (IEC 61755 series) and is associated with fibre specification standards (IEC 60793 series) and test methods (IEC 61300 series). The replacement work continues within the IEC 63267 family which consolidates and updates reference-connector requirements for enhanced macrobend multimode fibres.

Q: What are the key keywords?

A: Reference connector, 50 µm multimode, 850 nm, A1a fibre, optical interface, physical contact, attenuation reference, connector geometry.