1. ADVANCED TRENDS IN OPTICAL COMMUNICATIONS
SNS COLLEGE OF TECHNOLOGY
(An Autonomous Institution)
Sathy Main Road (NH 209), SNS Kalvi Nagar,
Saravanampatti (Post), Coimbatore-35
ADVANCED TRENDS IN OPTICAL COMMUNICATIONS
Prepared By
Dr. J. Ajayan., MTech., PhD.,
EC-413 OPTOELECTRONIC DEVICES
13/10/2017

2. RECALL
A S WE ENTER THE NEW MILLENNIUM, we are seeing dramatic changes in the telecommunications industry that have far-reaching implications for our lifestyles. There are many drivers for these changes. First and foremost is the continuing, relentless need for more capacity in the network.
This demand is fuelled by many factors. The tremendous growth of the Internet and the World Wide Web, both in terms of number of users as well as the amount of time and thus bandwidth taken by each user, is a major factor.
A simple example of the latter phenomenon is the following: An average voice phone call lasts about 3 minutes; in contrast, users connecting to the Internet via dialup lines typically stay on for an average of 20 minutes. So an Internet call brings in about six times as much traffic into a network as a voice call.
Internet traffic has been doubling every four to six months, and this trend appears set to continue for a while.

4. INTRODUCTION

5. Fiber Optics Communication Equipments:
Optical Switch
Optical Multiplexer
Optical Amplifier
Fiber Optic Cables
Optical Transport Equipment
And so on……..
Optical Switch
Optical Multiplexer
Optical Amp

6. History of Optical Fibre Communications
1966 – suggestion to use optical fiber (Kao & Hockham)
1970 – Corning Glass optical fiber with 20 dB/km near 1 μm
Semiconductor Laser with CW operation at room temp.
1980 onwards – wide spread use of Optical Fiber Communication using SMF and MMF
1990 – used Optical amplification (for increased repeater spacing) and Wavelength-division multiplexing (WDM) for increased data rate.
Resulted in a data rate of 10 Tb/s by 2001.

7. Advantages of Optical Fiber Communication (Fiber Optics)
Very high bandwidth ( GHz, typ.)
Very low attenuation (lowest 0.16 dB/km)
Immune to EMI
Data security (almost impossible to tap information)
Lower system cost (fewer repeaters due to low attenuation of fibers)
Small size and low weight
Very low Bit Error Rate ( < typically)

8. Basics of Optical Fibre Communication
An Optical Fiber Communication System consists of
Transmitter
Optical source (LED or Laser diode) + driver circuit
Optical Fibre
Single mode fibre, or
Multimode fibre
Receiver
Photodetector PIN or APD + receiver circuit

9. A Modern Optical Communication System for Telecom with WDM and Optical Amplifiers
Source: Gerd Keiser, Optical Fiber Communications, 4th ed., McGraw-Hill, 2008: Chapter 10.

10. Source: Nobel Lecture, 2009, CK Kao, “Transmission of Light in Fiber for Optical Communication”

11. Fibre Optics Telecom applications Networking applications
Primarily SMFs
Networking applications
Mostly SMFs (FTTH)
Fibre optic Sensing
SMF and MMF
Medical applications
Mostly MMF, or bundle fibres (light pipes
Industrial applications
Mostly MMF

12. Fibre types – how do they differ?
Source: P.Polishuk, “Plastic Optical Fibers Branch Out”, IEEE Commn. Mag., Sep.2006, pp

13. Source: P. Polishuk, “Plastic Optical Fibers Branch Out”, IEEE Commn
Source: P.Polishuk, “Plastic Optical Fibers Branch Out”, IEEE Commn. Mag., Sep.2006, pp

14. SUMMARY