Overview
IEC TR 62547:2013 - "Guidelines for the measurement of high‑power damage sensitivity of single‑mode fibre to bends - Guidance for interpretation of results" - defines two laboratory methods to evaluate how single‑mode optical fibres respond when high optical power is launched into bends. The report provides procedural guidance, safety considerations, recommended apparatus, interpretation guidance and example data. This second edition updates guidance for B6 (bend‑insensitive) single‑mode fibres and refines the analysis for test method 2 (maximum temperature specification).
Key topics
- Scope and limits
- Applies mainly to un‑cabled, un‑buffered single‑mode fibres; buffered/cabled fibres may behave differently.
- The methods are not intended as routine production tests nor as specification clauses for standard product datasheets.
- Two complementary test methods
- Test method 1 - Failure time characterisation: measures time‑to‑catastrophic failure as a function of launched power, bend angle, and bend diameter.
- Test method 2 - Equilibrium temperature measurement: measures coating temperature at bends under steady power to assess thermal loading and enable qualitative comparison with failure data. Results from the two methods are only qualitatively comparable.
- Apparatus and measurement elements
- Suggested equipment includes: light source, isolator, bend jig, receiver/attenuator, thermal imaging camera (IR/FLIR), oven (for some conditioning), camera and computer for logging.
- Safety considerations
- Eye safety, risk of fire/flame, coating decomposition products, fibre fuse initiation, and risk to downstream components are explicitly addressed.
- Interpretation and outputs
- Guidance on reporting items, analysis of equilibrium temperatures, and examples (e.g., plots of coating temperature vs launched power and bend radius). The report includes annex material linking equilibrium temperature to long‑term safe power limits.
Applications
- Who uses it: fibre manufacturers, independent test laboratories, research groups, standards committees, and system designers concerned with high‑power deployments (e.g., high‑power amplifiers, specialized sensing or laser delivery systems).
- Practical uses
- Assessing the sensitivity of single‑mode optical fibres to high‑power damage at bends to inform handling limits.
- Estimating maximum safe launched power for a given bend radius and fibre construction (qualitatively).
- Informing product design choices (coating selection, routing, bend mitigation) and laboratory safety procedures.
Related standards
- IEC 60793‑2‑50 (single‑mode fibre specifications) - referenced as a baseline for normal bend‑radius specifications.
- ITU‑T G.654 - cited in examples and comparative plots for certain single‑mode fibre categories.
Keywords: IEC TR 62547:2013, sensitivity of single‑mode optical fibres to high‑power damage at bends, bend‑insensitive fibre, failure time characterisation, equilibrium temperature measurement, bend radius, coating temperature, test method.