This document provides an overview of optical fiber communication. It discusses the basic components and materials used in optical fibers, including the core, cladding and protective layer. The document also explains the working principle of total internal reflection that optical fibers use to transmit data. Some key advantages are that optical fibers are lighter weight, safer, and more flexible than metal wires. Applications discussed include use in telecommunications, local networks, medical imaging, and more.

1. OPTICAL FIBRE COMMUNICATION
P.RANJIT
12W61A0485

2. CONTENTS
 INTRODUCTION
 Cross section area of optical fibre
 Materials used for optical fibre
 Block diagram of optical fibre with transmitter and receiver blocks
 Working principle
 Advantages
 Disadvantages
 Applications in various fields

3. INTRODUCTION
 Optical fibre is a coaxial cylindrical arrangement of two homogenous
dielectric material
 It is flexible, transparent fibre made of silica or plastic slightly thicker than
human hair
 Its working is based on Total Internal Reflection
 they permit transmission over longer distances and at higher
bandwidths (data rates) than wire cables.
 Specially designed fibres are used for a variety of other applications,
including sensors and fibre lasers.

4. Cross section area of optical fibre
Optical fibre consists of three layers
Core
Cladding
Protective or jacket layer

5. MATERIALS USED FOR OPTICAL FIBER
 Optical fibers are generally made up of glass and
plastic
 There are different types of glass fibers are there are
 Glass fibers
CORE CLADDING
Geo2+sio2 sio2
Sio2 B2o3-sio2

6. MATERIALS USED FOR OPTICAL FIBER
Halide Glass Fibers
Active Glass Fibers
Chalcogenide Glass Fibers

7. Plastic fibers
POF (plastic optic fibre)
PMMA (poly methyl metha crylate)
PFP (pre fluorinated polymers)

8. Block diagram

9. Working Principle
 As the angle of incidence is beyond the critical angle, then the light ray
gets reflected with in the denser medium rather than causing refraction.
This is called ‘TOTAL INTERNAL REFLECTION’

10. TOTAL INTERNAL REFLECTION
Observed in optical fibre

11. Advantages
 Weight - Fibre optic cables are much thinner and lighter than
metal wires.
 Safety - Since the fibre is a dielectric, it does not present a
spark hazard.
 Flexibility - An optical fibre has greater tensile strength than
copper or steel fibres of the same diameter.
 Cost - The raw materials for glass are plentiful, unlike
copper. This means glass can be made more cheaply than
copper.

12. Disadvantages
 Cost - Cables are expensive to install but last longer than copper
cables.
 Transmission - transmission on optical fibre requires repeating at
distance intervals.
 Protection - Optical fibres require more protection around the cable
compared to copper.
 Affected by chemicals - The glass can be affected by various
chemicals including hydrogen gas (a problem in underwater cables.)

13. APPLICATIONS
 Telephones
 Internet
 LANS-Local area networks
 CATV-For video, voice and internet
connections
 Security-closed circuit TV and intrusion sensors

14. APPLICATIONS
 IN MEDICAL FIELD
 For viewing internal parts of body with
instruments like fibre scope , bronchoscope
 Dermatology-for wrinkle and hair removal