Overview
IEC 61300-3-30:2003 specifies a repeatable test method to assess end‑face geometry of guide‑pin based single‑ferrule multifibre connectors. The standard prescribes how to measure the polish angle (X and Y end‑face angles), fibre position (protrusion or undercut relative to a best‑fit plane) and core dip (for multimode fibres) using three‑dimensional interferometric surface analysis. It defines measurement regions, data‑processing steps and conventions needed for consistent evaluation of multifibre ferrules.
Key topics and technical requirements
- Scope: Examination of end‑face geometry for guide‑pin aligned multifibre ferrules; primary attributes are fibre protrusion/undercut, end‑face angle relative to guide pin bores, and multimode core dip.
- Apparatus: Ferrule holder, rigid positioning stage and a 3D interferometry analyser capable of resolving fibre heights with accuracy better than ±50 nm.
- Measurement regions:
- Region of interest (ROI) centred on the fibre array
- Extracting regions around each fibre (adhesive/fibre end areas)
- Fitting region (ROI excluding extraction regions)
- Averaging regions for singlemode and multimode fibres; for MM fibres a core fitting region and an annular ring are used to compute core dip
- Analysis method (summarized):
- Map surface within ROI using interferometer
- Remove extraction regions, fit a biparabolic surface to the remainder
- Subtract the fit, remove highest 3% outliers, select highest 20% for best‑contact points
- Fit a plane to those points referenced to the guide‑pin bore axis to derive X/Y polish angles and normal fibre heights (protrusion/undercut)
- For MM fibres, calculate core dip as the difference between core average height and surrounding annular average
- Data conventions: Annexes provide formulae, sign conventions for angles and fibre counting conventions to ensure consistent reporting.
Practical applications
- Quality control and acceptance testing of multifibre ferrules and connectors during manufacture and incoming inspection.
- R&D and process validation for polishing and ferrule design to optimize physical contact and minimize insertion loss.
- Failure analysis and field lab diagnostics where end‑face geometry impacts mating performance.
- Specifying and verifying supplier compliance in procurement of connector assemblies.
Who should use this standard
- Connector and transceiver manufacturers
- Fiber assembly and polishing process engineers
- Test laboratories and certification bodies
- Network equipment purchasers and QA teams
Related standards
- IEC 61300 (general series) - Part 1 (general guidance) and other Part 3 documents for examinations and measurements. Refer to IEC 61300 series for complementary test methods and definitions.
Keywords: IEC 61300-3-30:2003, fibre optic, multifibre connector, ferrule end‑face, polish angle, fibre protrusion, core dip, 3D interferometry, guide pin alignment.