Hello everyone!
Today, I want to write about optical cables. This is a very important topic.
The task of the cable is to protect the optical fibers. The type and level of protection depending on the environment where the optical cable is installed. By the term optical cable, we mean all the elements: jacket, aramid fiber- Kevlar, PVC tubes, fiberglass rod, optical fibers, etc. There are a large number of different types of optical cables, it depends on the environment where it is installed and the number of optical fibers.
Optical cables can be installed aerial, direct-buried, underground or underwater. The cable should always protect the fibers from the penetration of water and moisture, and in addition, depending on the environment where it is installed – protection for sunlight, tensile forces, rodents, fire, etc.
Figure 1. Optical cables
Many elements of cable (figure 2.) are involved in optical fiber protection. First, the optical fiber is always supplied with a buffet coating(primary buffer coating), whose diameter is about 200 to 250 um. In loose tube cables, the optical fibers are grouped into PVC tubes (buffer tubes). These tubes contain gel. The next protection is a fiberglass rode, it prevents large cable bending. There are also aramid fibers - Kevlar. And finally, there is the jacket. There can be multiple layers of jackets. And there are armored cables.
In general, optic cables can be divided into two major groups:
loose tube cables and
tight buffer cables.
Loose tube cables are usually used for outdoor applications and tight buffer cables are used for indoor applications.
Figure 2. Elements of optical cable
The tight buffer cables are:
simplex,
zipcord,
distribution and
breakout cables.
The loose tube cables are:
microcables,
ribbon cables,
armored cables,
high fiber count cables,
aerial cables (ADSS, Fig8, OPGW, etc).
There are also special optical cables, these are:
hybrid cables. They contain a combination of SM and MM fibers. They are most often used in LAN networks, where MM fibers are used, and SM fibers are used for future needs. And,
composite cables. They contain a combination of optical fibers and wires for the power supply.
This is the end of this article. I will continue to write about this theme in the next article >> Optical cables (2): Tight buffer cables.
Thank you!
