What is the outside coating diameter of the fiber in loose buffered cables?

What is the outside coating diameter of the fiber in loose buffered cables?

• A. 250um
• B. 150um
• C. 300um
• D. 500um

Answer: (A)

In fiber optics, each strand of glass fiber is protected by a polymer coating after the core and cladding are formed. In loose buffered cables, this coating remains with the fiber, and the term “outside coating diameter” refers to the diameter of that protective coating, not the cable jacket. The standard outer diameter of this coating is 250 micrometers. This comes from the typical arrangement where the glass fiber has a 125 µm cladding, and about 62.5 µm of coating sits on each side, totaling 250 µm. The other numbers would imply a thinner or thicker primary coating than is standard for most telecom fibers.

In fiber optics, each strand of glass fiber is protected by a polymer coating after the core and cladding are formed. In loose buffered cables, this coating remains with the fiber, and the term “outside coating diameter” refers to the diameter of that protective coating, not the cable jacket. The standard outer diameter of this coating is 250 micrometers. This comes from the typical arrangement where the glass fiber has a 125 µm cladding, and about 62.5 µm of coating sits on each side, totaling 250 µm. The other numbers would imply a thinner or thicker primary coating than is standard for most telecom fibers.