The More You Know: Fiber Terms 101

February 9, 2017 at 8:00 AM


They say knowledge is power, so we are here to empower you! The fiber terms 9/125, 50/125 and 62.5/125 might look like algebra to you, but here we’ll explain what they mean, how to read them and we even have a diagram and video to help enhance your educational experience.


The most common fiber cable sizes are 9/125, 50/125 and 62.5/125. These numbers refer to the diameter, in microns, of the core and cladding of a fiber optic cable. The leading numbers (9, 50 and 62.5) refer to the diameter of the fiber cable's core in microns. The trailing number (125) is the diameter (in microns) of the outside of the fiber cable's cladding. The cladding is a special coating that keeps the light from escaping the glass core of the cable. For quick reference, 9/125 is a single-mode fiber cable, 50/125 and 62.5/125 are multimode fiber cables.


Here is a diagram of the fiber core and cladding so you can see exactly what we’re talking about:



Click on the image below to watch our video that further explains the different fiber types.


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