Fiber optic cables

• An optical fiber cable is a cable containing one or more optical fibers that are used to carry light.
• A real fiber optic cable is made of glass which is incredibly pure to allow light to pass through over very long distances. The glass is then coated in two layers of plastic.

How optic cables work

• Fiber optic cables carry communication signals using pulses of light generated by small lasers or light-emitting diodes.
• The center of each strand called the "core" provides the pathway for light to travel.
• Which is surrounded by a layer of glass called "cladding" that reflects light inward to avoid loss of signal and allow the light to pass through bends in the cable.

Types of fiber optic cables

• Mainly fiber optic is categories into two types. One is single-mode, other is multi-mode.

Single-mode fiber optic cable

• Single-mode fiber optic cable use laser light transmitters to send information.
• High light power is needed here because information uses to travel over single-mode over long distances.
• The range that single-mode cable can cover is 100 KM.

Multi-mode fiber optic cable

• Multi-mode fiber optic cable LED light transmitters because light do not have to travel the long distances.
• This light use less power as well because the distance that has to be covered by this cable is much shorter than single-mode cable.
• The range that multi-mode cable can cover is 2 KM.

• Below image shows the different types optical fiber cables.

Below table shows the different types of cables and it's details.

Type of Fiber Optic Cable	Distance Traveled	Core Diameter Size	Description
Plastic cable	A few meters	1mm	Best for short and rugged applications. Typically not used for data transmission.
Plastic-coated silica cable.	A few meters.	1 mm	It has a glass core and plastic cladding. Used for research, medical, material processing.
Single-index mono-mode fiber cable.	Extremely long distances.	Very narrow core.	Allow for one data stream or mode. Carries more bandwidth but in narrow spectral width.
Step-index multi-mode cable.	Short distances.	Large diameter core with high dispersion characteristics.	The cable is designed for the LAN environment and light is typically generated with a LED.
Graded-index multi-mode cable.	Longer distances than step-index.	Large diameter.	Multiple layers of glass that contain dispersion's enough to provide increases in cable distances.

Below image shows the different types optical fiber cable connectors.

Advantages

• Fiber optic cables have a much greater bandwidth than metal cables. This means that they can carry more data.
• Fiber optic cables are less susceptible (damaged) than metal cables to interference.
• Fiber optic cables are much thinner and lighter than metal wires.
• Data can be transmitted digitally (the natural form for computer data) rather than analogically.

Disadvantages

• Cables are expensive to install but last longer than copper cables.
• Transmission on optical fiber requires repeating at distance intervals.
• Optical fibers require more protection around the cable compared to copper.

History

• The concept of light transmission has existed since the early 1840’s when French inventors Daniel Colladon and Jacques Babinet demonstrated the guiding of light over distance by refraction.