FIBER OPTICS

A TECHNICAL SEMINAR

By RAHUL GUPTA Instructor MISS. NAZIA KHAN

INTRODUCTION

1. An optical fiber is a flexible, transparent fiber made of high quality extruded glass (silica) or plastic, slightly thicker than a human hair

2. It can function as a waveguide, or “light pipe”, to transmit light between the two ends of the fiber

3.These fibers are used as an alternative to conventional copper wire

5.Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication.

WHAT IS AN OPTICAL FIBER

An optical fiber is a wave guide for light consists of :

core inner part where wave propagates

cladding outer part used to keep wave in core

buffer protective coating

jacket outer protective shield

can have a connector

too

Optical fiber is based on Total internal reflection

When light traveling in an optically dense medium hits a boundary at a steep angle (larger than the critical angle for the boundary), the light is completely reflected. This is called total internal reflection.

This effect is used in optical fibers to confine light in the core.

Light travels through the fiber core, bouncing back and forth off the boundary between the core and cladding..

Basic Principle of optical fiber

LOGIC BEHIND OPTICAL FIBER TRANSMISSION

HistoryFiber optics, though used extensively in the modern world, is a fairly simple, and relatively old, technology. Guiding of light by refraction, the principle that makes fiber optics possible

Fiber optics first demonstrated by Daniel Colladon and Jacques Babinet in Paris in the early 1840s. John Tyndall included a demonstration of it in his public lectures in London, 12 years later.

When the light passes from air into water, the refracted ray is bent towards the perpendicular... When the ray passes from water to air it is bent from the perpendicular..

Tyndall also wrote about the property of total internal reflection in an introductory book about the nature of light in 1870:

Principle of operation In optical fiber

An optical fiber is a cylindrical dielectric waveguide (nonconducting waveguide) that transmits light along its axis, by the process of total internal reflection. The fiber consists of a core surrounded by a cladding layer, both of which are made of dielectric materials. To confine the optical signal in the core, the refractive index of the core must be greater than that of the cladding. The boundary between the core and cladding may either be abrupt, in step-index fiber, or gradual, in graded-index fiber

Types Of Optical Fiber

step-indexmultimode

step-indexsingle mode

Optical fiber can be used as a medium for

telecommunication and computer networking because it is flexible and can be bundled as cables

Fibers have many uses in remote sensing.

Uses of optical fiber

It is especially advantageous for long-distance communications, because light propagates through the fiber with little attenuation compared to electrical cables.

ADVANTAGES OF OPTICAL FIBER

•Small Size

•Light Weight

•High Bandwidth

•No Short Circuits

•Fewer Repeaters

•Noise Immunity

•Transmission Security

DISADVANTAGES OF OPTICAL FIBER

•Cost

•Taps

•Fear of New Technologies

THANK YOU

QUESTION