How Much Do You Know About the Fiber Optic Cable?

What is fiber optic cable?

A fiber optic cable is a network cable that contains strands of glass fibers inside an insulated casing. These fiber optic cables are designed for long distance and very high bandwidth network communications. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed. Different types of cable are used for different applications, for example long distance telecommunication, or providing a high speed data connection between different parts of a building.

Fiber optic cables carry communication signals using pulses of light. While expensive, these cables are increasingly being used instead of traditional copper cables, because fiber offers more capacity and is less susceptible to electrical interference. So called Fiber To The Home (FTTH) installations are becoming more common as a way to bring ultra high speed Internet service to residences.

What are the color codes for fiber optic cable?

The fibers in optical fiber cables are numbered according to their color code, which simplifies connecting hardware installation and connector termination as well as further administration and testing of the cabling system.

fiber optic color code

The fibers are numbered in accordance with the individual standard color code given in figure 1. 250- and 900-micron buffer coatings are subject to color-coding. In modular design multifiber cables, the same color coding is applied with respect to modules.

In loose tube cables, with over 12 fibers in one tube, fibers can be combined to form a single unit fixed by colored threads.

In some cases to facilitate pair grouping the fibers are painted the same colors with collar marks every 2-3 cm (0.8 – 1.2 in) on the second fiber of the pair.

Colored outer jackets or print may be used on Premises Distribution Cable, Premises Interconnect Cable or Interconnect Cord, or Premises Breakout Cable to identify the classification and fiber sizes of the fiber.

When colored jackets are used to identify the type of fiber in cable containing only one fiber type, the colors shall be as indicated in Table 1. Other colors may be used providing that the print on the outer jacket identifies fiber classifications in accordance with subclause 4.3.3. Such colors should be as agreed upon between manufacturer and user.

Unless otherwise specified, the outer jacket of premises cable containing more than one fiber type shall use a printed legend to identify the quantities and types of fibers within the cable. Table 3 shows the preferred nomenclature for the various fiber types, for example “12 Fiber 8 x 50/125, 4 x 62.5/125.”

When the print on the outer jacket of premises cable is used to identify the types and classifications of the fiber, the nomenclature of Table 3 is preferred for the various fiber types. Distinctive print characters for other fiber types may be considered for addition to Table 1 at some future date.

fiber optic cable color code


1. Natural jackets with colored tracers may be used instead of solid-color jackets.

2. Because of the limited number of applications for these fibers, print nomenclature are to be agreed upon between manufacturer and end-user.

3. Other colors may be used providing that the print on the outer jacket identifies fiber classifications.

4. For some premises cable functional types (e.g, plenum cables), colored jacketing material may not be available. Distinctive jacket colors for other fiber types may be considered for addition at some future date.

How does a fiber optic cable work?

To understand how a fiber optic cable works, imagine an immensely long drinking straw or flexible plastic pipe. For example, imagine a pipe that is several miles long. Now imagine that the inside surface of the pipe has been coated with a perfect mirror. Now imagine that you are looking into one end of the pipe. Several miles away at the other end a friend turns on a flashlight and shines it into the pipe. Because the interior of the pipe is a perfect mirror, the flashlight’s light will reflect off the sides of the pipe (even though the pipe may curve and twist) and you will see it at the other end. If your friends were to turn the flashlight on and off in a morse code fashion, your friend could communicate with you through the pipe. That is the essence of a fiber optic cable.


A transmitter is a device found at the beginning of a fiber optic cable network. The transmitter takes information and turns it into a pulsing light wave that can be sent along a fiber optic cable. A lens is then used to send the light into a fiber optic cable. The light will travel along the fiber optic cables more quickly and with less signal degradation than occurs when sending data along traditional coper wires.

Fiber Optic Cable

The core of a fiber optic cable is made of a very clear glass tube that transmits light. This glass core is surrounded by a coating called cladding. Light will travel down the fiber optic tube in a straight line. Unfortunately, not all fiber optical cables can be laid along a straight path, so the cladding surrounding the cable is mirrored. The light bounces off of the mirrors on the cladding and is directed back into the fiber optic core to continue its journey along the cable.

Optical Regenerator

Sometimes a light signal must travel through a fiber optic cable over a very long distance. Although signal degradation is minimal in a fiber optic cable, some degradation does occur. When a cable covers a long distance, optical regenerators are placed at certain intervals along the cable. Optical regenerators are fibers that have been treated with a laser. The molecules in the fiber allow the signal traveling through the fiber optic cable to take on laser properties themselves, which strengthens the light signal. Optical regenerators essentially strengthen the light signal that is traveling through a fiber optic cable.

Optical Receiver

At the end of the fiber otic network there is an optical receiver. This receiver is essentially performs the opposite function of the transmitter found at the beginning of the system. Optical receivers receive the light signal from the fiber optic cable and turn it back into information that a computer or television know how to understand and use. It then sends the decoded signal to the computer or television.

Types of loose tube fiber optic cables

FiberStore have many types of loose tube fiber optic cables, such as All -Dielectric Loose Tube Cables, Gel-Filled Loose Tube Cables, Double-Jacket Loose Tube Cables, Central Loose Tube Cables.