Overview
IEC PAS 63267-3-31:2020 specifies end-face geometry and dimensional limits for flat PC rectangular polyphenylene sulphide (PPS) ferrule optical interfaces used with multimode fibres. It targets a single-row 12‑fibre ferrule (interface variant 1112, nominal ferrule cross-section 2.45 mm × 6.4 mm, 0.25 mm pitch) and defines the end‑face parameters needed to meet longitudinal‑offset requirements for reliable fibre‑to‑fibre interconnection. Ferrules in this PAS are suitable for use in performance categories C, U, E, and O as per IEC 61753‑1.
Key topics and technical requirements
- End‑face geometry parameters: Defines the measurable features that affect longitudinal offset including fibre protrusion, fibre array minus‑coplanarity, adjacent fibre height differential, end‑face X/Y angles and radii, fibre tip spherical radius, and core dip.
- Dimensional limits and tolerances: The PAS specifies limits applicable to the central end‑face region around the 12 fibres (nominal pitch 0.25 mm). Representative limits in the document include:
- X‑angle (ferrule surface slope): ±0.15°
- Y‑angle: ±0.2°
- Fibre height (protrusion): 1 – 3.5 µm
- Adjacent fibre height differential: 0 – 0.3 µm
- Core dip control: ~120 nm (document reference)
- Material and mechanical context: Applies to PPS ferrules with Young’s modulus ~15–20 GPa and specifies recommended ferrule compression (axial force) range (≈7.8 N to 11.8 N) for mating.
- Measurement method: End‑face geometry shall be measured in accordance with IEC 61300‑3‑30 (polish angle and fibre position measurement procedures).
- Performance considerations: Separate geometry limits are provided depending on whether fewer or greater than 50% of the fibres show core dip; minus‑coplanarity and geometry limits are defined to control longitudinal offset during mating.
Applications and who uses it
- Connector and ferrule manufacturers: for design, tooling, and production tolerances of PPS rectangular ferrules.
- Quality and test laboratories: to verify end‑face geometry and ensure compliance using IEC 61300‑3‑30 test methods.
- System integrators and spec writers: to select compatible connectors and to specify intermateability and loss expectations for multimode links in data centers, enterprise cabling and telecom premises.
- Procurement and compliance teams: to ensure sourced components meet required IEC interface and performance categories.
Related standards
- IEC 61754 series - ferrule and connector interface dimensions
- IEC 61300‑3‑30 - end‑face measurements (polish angle, fibre position)
- IEC 61753‑1 - performance categories for fibre optic interconnecting devices
- IEC 61755‑1 - connector performance intermateability (referenced for mating rules)
Keywords: IEC PAS 63267‑3‑31:2020, fibre optic connector, flat PC PPS rectangular ferrule, end face geometry, longitudinal offset, multimode fibres, ferrule dimensions, IEC 61754, IEC 61300‑3‑30.