IL @ 1550 higher than 1310
A connector, or an entire product design, showing a significantly higher Insertion Loss at 1550 than at 1310 indicates the likely presence of a stress point on the fiber somewhere in the cable assembly—most likely a fiber bend that exceeds operating bend radius, or a fiber “pinch” or microbend somewhere within the product. The higher the stress (larger the bend), the higher the Insertion Loss @ 1550 compared to 1310. But whereas a core-offset problem mentioned above are often normal results of raw-material selection, any excess stress directly on a fiber represents a serious risk to product reliability, and thus IL values @ 1550 are particularly important to monitor and troubleshoot.
Even with advent of “reduced bend radius” fiber, it is excellent practice to test all products at 1550. Doing so may identify a serious product flaw, particularly in products which have fiber routed within an enclosure (such as within a cassette or a cabinet or a ribbon fan-out transition). If your product Insertion Loss @ 1550 is significantly higher than @1310, you very likely have a product with fiber under stress, and you need to understand the cause.
READ THE BLOG: Insertion Loss Troubleshooting Tip: Singlemode 1310 vs. 1550
Additional resources from the FOC team include:
- Category Resource: FOC Test Page
- Glossary, Acronyms, Military Specifications for Connectors: http://bit.ly/2a2EFn8
- Q&A Resource: email technical questions to AskFOC@focenter.com
Have questions about this FOC Tip?
Contact FOC with questions at: (800) 473-4237 / 508-992-6464 or email: FiberOpticCenter@focenter.com and we will respond ASAP.