Fiber optic communication system Optical Fibre Communication Fiber

Fiber optic communication system

Optical Fibre Communication

Fiber optic communication system • Light is used as transmission medium • Instead of using electromagnetic waves light waves are transmitted through fiber optic cable • The information to be transmitted is converted in to electrical signal • Analog electrical signal is converted in to series of digital pulses using A/D converter

Fiber optic communication system Optical Sources • Digital pulses are used to flash powerful light source on and off very rapidly • For simple low cast system LEDs are used as light source • It is a semiconductor device that generates low intensity red light beam • Commonly used light source is solid state laser • It generates high intensity single frequency light beam

Fiber optic communication system Optical detector • The light beam pulses are fed to fiber – optic cable to transmit long distance • At the receiving end photo cells are used to detect the light pulses • Photo cells convert light pulses in to electrical signal

Fiber optic communication system Optical detector • The electrical pulses are amplified and converted in to digital form • Digitized signal is given to D/A converter • It is the original voice or video signal • In very long transmission repeater stations are used

Fiber optic communication system Application • Long distance telephone system • Inter connect computers within a large building • Carry control signals in aero planes and ships • Communication systems in military • Nuclear plant instrumentation

Fiber optic communication system Advantages • Light weight • Larger information carrying capacity • Immunity to interference • Does not affected by temperature and environmental changes • Requires less space

Fiber optic cable • It consists of a central core and outer cladding • Types – Glass and Plastic fiber

Fiber optic cable Glass fiber • Superior optical quality • Fragle and more expensive • More costly • Propagate light more efficiently • Used for high speed application • Used for long distance transmission

Fiber optic cable Plastic fiber • Less expensive

Fiber optic cable Varieties of optical fiber available • Silica clad silica ( glass core with glass cladding) • Plastic clad silica ( glass core with plastic cladding) • Plastic core with plastic cladding