Fiber Optic Communication

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  • Topic: Optical fiber, Fiber-optic communication, Laser
  • Pages : 4 (983 words )
  • Download(s) : 110
  • Published : April 11, 2013
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Introduction:
Now we are in the twenty first century, the era of ‘Information technology’. There is no doubt that information technology has had an exponential growth through the modern telecommunication systems. Particularly, optical fiber communication plays a vital role in the development of high quality and high-speed telecommunication systems. Today, optical fibers are not only used in telecommunication links but also used in the Internet and Local area networks (LAN) to achieve high signaling rates.

What is fiber optic communication?
Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information. Electrical signal

Optical Transmitter
Signal input

Optical channel
Optical Receiver

Electrical signal

Signal output

Simple block diagram of optical fiber communication system
Figure: 01

How does the optical Fiber transmission system work?

Figure: 02 show the basic components in the optical fiber communication system. The input electrical signal modulates the intensity of light from the optical source. The optical carrier can be modulated internally or externally using an electro-optic modulator (or) acousto-optic modulator. Nowadays electro-optic modulators are widely used as external modulators which modulate the light by changing its refractive index through the given input electrical signal. In the digital optical fiber communication system, the input electrical signal is in the form of coded digital pulses from the encoder and these electric pulses modulate the intensity of the light from the laser diode or LED and convert them into optical pulses. In the receiver stage, the photo detector like avalanche photodiode (APD) or positive-intrinsic-negative (PIN) diode converts...
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