IEC 61755-6-2:2018

Overview

IEC 61755-6-2:2018 is an international standard published by the International Electrotechnical Commission (IEC) focusing on fibre optic interconnecting devices, specifically the connector optical interfaces for multimode physically contacting fibres. This part of the IEC 61755 series defines the dimensional limits and performance criteria of non-angled polished multimode reference connectors with a 50 µm core diameter. These connectors utilize selected IEC 60793-2-10:2015 A1a fibres and operate at a wavelength of 850 nm. The standard is key for ensuring precise fibre-to-fibre interconnections, mainly for attenuation measurement applications in both field and factory environments.

Key Topics

• Reference Connector Specifications
  Defines the geometric dimensions and tolerances of non-angled polished reference connectors with cylindrical ferrules to minimize measurement variation.

• Performance Grade for Reference Connectors
  Specifies one performance grade targeting low attenuation, with a maximum attenuation of 0.1 dB and a measurement uncertainty contribution of ±0.071 dB as measured under the IEC 61300-3-4 procedure.

• Dimensional and Geometric Control
  The focus is on controlling lateral, angular, and longitudinal offsets between mating fibres to reduce attenuation variability.

• Use of Selected A1a Fibre
  Requires termination of the reference connector using selected IEC 60793-2-10:2015 A1a multimode fibre to ensure consistent optical characteristics.

• Attenuation Measurement Uncertainty
  Discusses the factors contributing to measurement uncertainty, including fibre parameter mismatches and connector alignment, with guidelines provided in an informative annex.

• Application of Reference Adapters
  The standard considers reference adapters as part of the measurement system to maintain consistent attenuation levels when mating connectors.

Applications

IEC 61755-6-2:2018 is primarily applied in optical networks and manufacturing processes where accurate attenuation measurements for multimode fibres are critical. Its use ensures consistent results for:

• Field Testing and Maintenance
  Engineers and technicians use reference connectors conforming to this standard to perform attenuation measurements and verify network integrity onsite.

• Factory Calibration and Quality Control
  Manufacturers of fibre optic components apply the standard to guarantee repeatability and reliability of connector performance during production.

• Standardization of Fibre Optic Interconnections
  Provides a uniform basis for compatibility between fibre optic components from different suppliers, ensuring interoperability in global optical communication systems.

• Measurement Systems in Telecommunications
  Supports high-quality testing setups, reducing measurement uncertainty which is crucial in high-speed multimode fibre network deployments.

Related Standards

• IEC 60793-2-10:2015 – Optic fibres product specification, specifically the sectional specification for category A1 multimode fibre used in this standard.

• IEC 61300-3-4 – Basic measurement procedure detailing attenuation measurements for fibre optic connectors, referenced for test methodology.

• Other Parts of IEC 61755 Series – Covering optical interface standards for other fibre types, connector geometries, and performance grades.

• ISO and IEC Electropedia – Provide standardized terminology necessary for consistent interpretation of fibre optics concepts.

Practical Value

Implementing IEC 61755-6-2:2018 ensures that multimode fibre optical interfaces used for attenuation measurements achieve minimal variability, improving the accuracy and repeatability of measurement results. The dimensional restrictions and performance grading reduce uncertainty caused by physical misalignments and fibre mismatches. This standard enables network professionals and manufacturers to maintain quality control and performance consistency in fiber optic connectivity, which is crucial for efficient operation and troubleshooting in modern optical networks.

Keywords: IEC 61755-6-2, fibre optic reference connector, multimode fibre, optical interface, fibre-to-fibre interconnection, attenuation measurement, optical connector standards, 50 μm core diameter, non-angled connector, IEC 60793-2-10 A1a fibre, IEC 61300-3-4, optical measurement uncertainty.