Fiber Optic Tubing: Why is Jacketing Important on Fiber Optic Cable?


Recently, Fiber optic cable has grown popular in the telecommunication industry. It is similar to an electrical cord. However, it has one or more optical fibers inside the casing. You might notice that a fiber optic strand is purely made of glass or plastic, which is easy to bend and requires a lot of protection. Hence, it would help if you had fiber optic tubing to cover them.

Table of Contents

How does the Fiber Optic work?

The fiber optic cable passes the information on/Off light pulses. However, this light is infrared, has no color, and thus, is invisible. The wavelength of infrared light is much longer than red light, which has the longest wavelength that your eyes can pick. That’s why infrared light is invisible to you.

In other words, the wavelengths your eyes can pick are from 400nm to 700nm. But, fiber optics are available at about 850nm, 1310, or 1500nm. The optical fiber becomes transparent to these higher wavelengths, and you get a signal with lower attenuation.

Note that fiber optic cables may become expensive as the wavelengths get higher. Hence, the fiber optics are implemented as follows to be within a budget:

  • For use within buildings, 850nm cable that can support up to 2 Km
  • To spread out the network within a city, 1310nm cable that can support up to 15 Km
  • For much greater distances, such as between cities, 1500nm cable that can support 80Km or more
fiber optic with connector

fiber optic with connector

Fiber Optic Cable Design

Usually, a light wave travels at a different speed in different materials. As it changes speed, it will change direction. It is the only reason a ray of sunlight bends when entering a magnifying glass from the air.

Similarly, a Fiber optic cable has components, which work on the same principle of total internal refraction. That way, the light travels from one end of the line to the other. Following are the elements of a Fiber Optic Cable.

Core and cladding

The fiber optic cable core is a cylinder of glass or plastic that runs throughout the cable length. It works to guide the light ray towards its destination. Outside the Core, there is a medium of lower index of refraction, called the cladding. This cladding may be of different types of glass or plastic.

Light travels between the core and cladding boundary due to the phenomenon of total internal refraction. The refracted ray of light hits far to the other part of the cladding and again refracts if the light and boundary angle is more significant than its critical angle. In this manner, the fiber transmits all the light waves to the other end of the cable without much energy loss.

Coating: loose buffer tube vs. tight buffer tube

When using fiber cables for a long distance, you will consider loose buffer tubes. These tubes make sure that the signals face low loss or attenuation. However, the open buffer is not applicable when you have to cover distances with sharp twists and turns. Thus, it would help if you ran the tight buffer optic cable to cover sharp bends.

The buffer is wrapped onto each fiber strand in a tight buffer tube with a smaller bend radius. Still, if you bend the cable more than the minimum bend radius, it will break down permanently.

fiber optic strands with tight tubes

fiber optic strands with tight tubes

Strength member

All fiber optic cables must have strength members. These are typically made with aramid fibers that do not stretch and cause kinks on the line. Additionally, it increases the cable’s stiffness and maintains its bend radius.

Outer jacketing

Jacketing is important since it covers all the components and forms an isolated optic cable. The colors of the jacketing may differ with the intention of usage. For example, outdoors, an optic cable will have a black jacket to protect the internal light rays from UV disturbance.

Types of Tubing

As discussed above, you need to enclose the jacketed fibers with fibrous polymers and then with a light plastic cover to form a cable. Then, you will terminate each end of the optic wire with a connector.

As the technologies evolve, the cables are now available in a wide variety of protection and sheathings. Thus, you have an option for each situation, whether you have to use it as a power line, connect it as an internet cable, install it in submarines or insert it into paved streets.

Here are the types of Jacketing that you can install on your cable.

Furcation tubing (-20C to +70C)

If you are low on a budget or you need it for laboratory use, then furcation jacketing is an excellent choice for you. In Furcation Tubing, the outer jacket is made of PVC. Also, it consists of a polypropylene inner fiber tube, Kevlar threads to make it fibrous, and a pull string to insert fiber.

PTFE tubing (-32C to +260C)

PTFE tubing has excellent temperature and chemical resistance, biocompatibility, superior lubricity, and precision tolerance. Also, it is not chemically reactive, so you can easily use it in chemically exposed areas.

PEEK tubing (-32C to +260C)

Peek tubing can give you high-level protection with high tensile strength and heat resistance. Moreover, it is resistant to chemicals, solvents, and fuels too.

PVC-monocoil (-20C to +105C) or Silicone monocoil (-55C to +250C)

Mono coils are made from loosely wound stainless steel, covered by PVC or silicon. It can be a good option since it provides good mechanical tolerance. Moreover, the silicon mono coil also gives superior flexibility to the wire.

Stainless steel square lock (+600C)

By overlapping joints of a metal strip, square lock tubing is made. It is crush-resistant, lighter in weight, and has minor ID bending than the interlock.

PVC-stainless steel interlock (-20C to +70C)

Interlock tubing covered with an industrial-grade PVC material is flexible and resistant to chemicals, sunlight, etc. Best for outdoor and industrial applications.


The primary concern in outdoor cabling is to protect the fiber from the damage of extreme weather, construction disasters, and animals. Whether hurricanes or heavy rain, it can bend the cables while breaking them apart very quickly. You have to armor the line heavily for such reasons as to remain safe and not spend money several times just on maintenance.

Here at Bloom, we offer custom wiring assembly and multiple types of connectors, so you’re your connection is made with attention to detail. To avail of our services, contact us now.