Just like those who drive around long after the engine service indicator lights up on the dashboard, there are folks out there who have likely been putting off getting their tester calibrated despite the email or LinkWare™ Live notification from Fluke Networks.
You might remember that just about three years ago, the DTX CableAnalyzer™ was officially retired. Since its discontinuation, Fluke Networks has continued to offer technical support, repair and calibration for this tester that was once touted as the ultimate time saver and brought testing to a whole new level when it was introduced in 2004.
Since today’s high-speed fiber networks use 850-nm vertical-cavity surface-emitting laser (VCSELs) transceivers, some may be confused about why light emitting diode (LED) light sources are used for testing. Understanding the differences between these two sources will certainly shed some light.
A History Lesson
Adopted by TIA, the nomenclature for multimode fiber found in the ISO/IEC 11801 standard includes the prefix “OM.”
Rather than the spiritual mantra you hear in yoga class, most sources in our industry state that the acronym OM comes from “optical multimode” which seems rather obvious. But when it comes to the various nuances of each type of OM, the differences aren’t quite as obvious.
Let’s take a closer look.
Often when we hear the term “bandwidth” we think of how much data can be sent over a fiber link. But when we look at fiber specifications, we typically see a specification for modal bandwidth, or effective modal bandwidth (EMB). This key characteristic of multimode fiber refers to how much data a specific fiber can transmit at a given wavelength, and it is dependent on another characteristic—differential mode delay.
So you’ve finished your fiber cable installation and are now on to the task of certifying the cable plant using an optical loss test set (OLTS) – it’s the tool you need for Tier 1 certification and the most accurate for measuring loss to ensure application support.
Unfortunately, you find some critical fiber links that far exceed your loss budget for the application. You now need to troubleshoot those links so you can fix the problems and move on to your next job. And the faster you can locate the problems, the faster you can fix them.
While it seems we can never hammer home enough the need to properly clean and inspect fiber end-faces since contamination remains the number one cause of fiber link failures, have you ever thought about what exactly you are cleaning and inspecting?
It’s always interesting at trade shows to learn what’s on the minds of end users, designers and technicians alike when it comes to testing. And this year’s BICSI Winter Conference was no different.
We’ve covered fiber insertion loss in plenty of past blogs, so by now we hope that you know it’s the amount of signal loss that occurs as the signal travels along a cable link. We also hope you know that insertion loss is directly related to the length of the cable—the longer the cable, the greater the loss—and that any connection point along the way (connectors, splices, splitters, etc.) also adds to the loss.
High speed applications are driving the deployment of multifiber MPO/MTP architectures in the data center, and it’s not just cloud and hyperscale data centers that are deploying these solutions. As the de facto interface for 40 Gig and 100 Gig switch-to-switch backbone data center applications that use parallel optics, MPO/MTP links are rapidly becoming commonplace in today’s enterprise data centers.