What is Fiber optic communication?

• The technique of transmitting data from one location to another by transmitting infrared light pulses using optical fiber is known as fiber optic communication. 
• Here, the light is in the form of a carrier signal that is changed to hold the data. 
• The fiber optic cables replace the electrical cables whenever long distance, high bandwidth, and resistance to electromagnetic interference are necessary.

Optical Fibers

• Fiber optics (optical fibers) are long, thin strands of very pure glass about the size of a human hair. They are arranged in bundles called optical cables and used to transmit signals over long distances.

How Fiber Optic Communication Works?

• Unlike copper wire-based transmission where the transmission entirely depends on electrical signals passing through the cable, fiber optics transmission involves the transmission of signals in the form of light from one point to the other. 
• Furthermore, a fiber optic communication network consists of transmitting and receiving circuitry, a light source, and detector devices like the ones shown in the figure.
• When the input data, in the form of electrical signals, is given to the transmitter circuitry, it converts them into a light signal with the help of a light source. 
• This source is an LED whose amplitude, frequency, and phases must remain stable and free from fluctuation in order to have efficient transmission. 
• The light beam from the source is carried by a fiber optic cable to the destination circuitry wherein the information is transmitted back to the electrical signal by a receiver circuit.

• The Receiver circuit consists of a photodetector along with an appropriate electronic circuit, which is capable of measuring the magnitude, frequency, and phase of the optic field. 
• This type of communication uses the wavelengths near the infrared band that is just above the visible range. Both LED and Laser can be used as light sources based on the application.

Fibre Optics Data transmission systems

• Fiber optic data transmission systems send information over fiber by turning electronic signals into light.  
• Light refers to more than the portion of the electromagnetic spectrum that is near to what is visible to the human eye.  
• The electromagnetic spectrum is composed of visible and near -infrared light like that transmitted by fiber, and all other wavelengths used to transmit signals such as AM and FM radio and television.  
•  Only a very small part of it is perceived by the human eye as light.