Ever notice how some fiber optic cables have a jacket in a different color than others? Jacket colors can vary depending on the specific type of fiber optic cable. All fiber optic cables consist of ultra-thin strands of optical fiber – typically glass or plastic – but they are available in different types. By familiarizing yourself with their jacket colors, you can identify fiber optic cables more easily.
A yellow jacket indicates single-mode fiber optic cable. Also known as mono-mode, single-mode fiber optic cable only supports a single mode of light propagation. If you come across a fiber optic cable with a yellow jacket, it’s safe to assume that it’s single mode.
Multi-mode fiber optic cable, on the other hand, typically has an orange jacket. Multi-mode fiber optic cable supports two modes of light propagation. With two modes of light propagation, it’s susception to interference. The two light modes may interfere with each other, resulting in a loss of data when used over long distances. With that said, multi-mode fiber optic cable offers faster data rates for short distances than single-mode fiber optic cable.
You can distinguish between single-mode and multi-mode fiber optic cables by inspecting the jacket. Single-mode fiber optic cables have a yellow jacket, whereas multi-mode fiber optic cables have an orange jacket.
While not as common as yellow or orange, some fiber optic cables have a blue jacket. A blue jacket indicates a polarization-maintaining fiber optic cable, which is essentially a type of single-mode fiber optic cable.
Polarization-maintaining fiber optic cables live up to their namesake by supporting polarized light. They propagate light in a way that allows it to become linearly polarized. Polarized-maintaining fiber optic cables are classified as single mode. Rather than an orange jacket, though, they feature a blue jacket.
Another color in which fiber optic cable jackets are available is aqua. Aqua indicates a laser-optimized multi-mode fiber optic cable. This type of multi-mode fiber optic cable supports light in wavelengths of 950 nanometers (nm) and 1300 nm.
You may come across fiber optic cables with a gray jacket as well. In the past, gray was the universal color for standard multi-mode fiber optic cables. However, it has since been replaced with orange. Older multi-mode fiber optic cables may still feature a gray jacket, but newer multi-mode fiber optic cables will almost always feature an orange jacket.