5 Best Practices for Certifying Next Generation Networks: Encircled Flux

This blog is part of a series: Intro | Cleaning and Inspection | Encircled Flux

What is encircled flux?

For multimode fiber, launch conditions or how light is coupled into a fiber can have a significant effect on optical loss measurements. Varying distributions of launch power can result in different attenuation measurements. Encircled flux simply refers to the method of distributing power among the modes of the fiber by controlling the launch spot size and angular distribution. Standards for encircled flux such as TIA-526-14-B have been established to produce consistency during testing especially at higher transmission speeds.

There are two ways to achieve encircled flux compliance—either through an externally conditioned jumper or managed inside the source. Externally conditioned jumpers used to be the only solution available. Due to the added cost and difficulty in managing these external jumpers, state-of-the-art Certification Kits manage encircled flux within the source equipment, assuring standards compliance while providing a simplified experience. Test equipment that meets the encircled flux standard will provide the most consistent and accurate test results and it is recommended that users update their test equipment to EF-compliant sources when possible.

Be sure to use an encircled flux compliant source/certification test kit to ensure consistent and repeatable measurements.

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Encircled Flux compliance provides consistent and repeatable launch Conditions preventing inaccuracies arising from overfilled/underfilled setups.