The attached narrated power point presentation explores the evolution and generations of fiber optics as well as recent trends in Optical Fiber Communications. An attempt has also been made to introduce a few emerging and exciting technologies in the area of Optical Communications. The material will be useful to KTU final year B Tech students who prepare for the subject EC 405, Optical Communications.

1. 1
Trends in Fiber Optic
Communications
MEC

2. 2
Contents
• Evolution of Fiber Optic Communications.
• Fiber Optic Communications System
Generations.
• Trends in Fiber Optic Communications.
• Some Exciting Optical Communication
Technologies.
• Conclusion.

3. 3
Evolution of Fiber Optic
Communication

4. 4
Evolution of Fiber Optic
Communication
• Optical fiber first developed in 1970 by Corning
Glass Works.
• GaAs semiconductor lasers developed for
transmitting light through fiber optic cables at
the same time.
• First generation fiber optic system:
- developed in 1975.
- used GaAs semiconductor lasers.
- operated at a wavelength of 0.8 μm.
- bit rate of 45 Megabits/second.
- 10 Km repeater spacing.

5. 5
Evolution of Fiber Optic
Communication
• Second Generation Fiber Optic System:
- developed in the early 1980’s.
- used InGaAsP semiconductor lasers.
- operated at a wavelength of 1.3 μm.
- operating at bit rates of upto 1.7 Gb/s
by 1987 on single mode fiber.
- 50 Km repeater spacing.

6. 6
Evolution of Fiber Optic
Communication
• Third generation fiber optic systems:
- developed in 1990.
- operating at a wavelength of 1.55 μm.
- a bit rate of upto 2.5 Gb/s on a single
longitudinal mode fiber.
-100 Km repeater spacing.
- discovery of Indium Gallium Arsenide.
- development of Indium Gallium Arsenide
photodiode by Pearsall.

7. 7
Evolution of Fiber Optic
Communication
• Fourth generation fiber optic systems:
- optical amplifiers replaced repeaters.
- utilized wavelength division multiplexing
(WDM) to increase data rates.
- transmission of over 11,300 Km at data
rates of 5 Gb/s using submarine cables
by 1996.

8. 8
Evolution of Fiber Optic
Communication
• Fifth generation fiber optic systems:
- use of Dense Wave Division Multiplexing
(DWDM).
- increase in data rates.
- concept of optical solitons.
- counteracting negative effects of
dispersion.

9. 9
Evolution of Fiber Optic
Communication

10. 10
Fiber Optics Time Line

11. 11
Trends in Fiber Optic
Communication
• All Optical Communication Networks.
• Multi – Terabit Optical Networks.
• Intelligent Optical Transmission Networks.
• Polymer Optical Fibres.
• Improvements in Optical Transmitter/
Receiver Technology.
• Improvements in Optical Amplification
Technology.
• Ultra-Long Haul Optical Transmission.
• High-Altitude Platforms etc.

12. 12
All Optical Communication
Networks
• Signals processed in optical domain
without any form of electrical manipulation.
• All signal processing and routing in optical
domain.
• No need to replace electronics when data
rate increases.
• Optical to electrical conversion and vice
versa adds to latency on the network,
limits maximum achievable data rates.

13. 13
Multi – Terabit Optical Networks
• World-wide need for increased bandwidth
availability.
• DWDM paves way for multi-terabit
transmission.
• Presently, 4 Tb networks using 40 Gb/s
data rate combined with 100 DWDM
channels exists.
• Search out for even higher bandwidth with
100 Gb/s.

14. 14
Intelligent Optical Transmission
Network
• Traditional optical networks unable to adapt
to fast growth of online data services due to
unpredictability of dynamic allocation of
bandwidth.
• Traditional optical networks rely on manual
configuration of network connectivity, is time
consuming, unable to fully adapt to the
demands of modern networks.
• Intelligent optical networks – the future trend.

15. 15
Intelligent Optical Transmission
Network
• Will first be applied in long-haul networks,
gradually to the network edges.
• Expected to adopt to the unpredictability of
bandwidth allocation.
• Applications: traffic engineering, dynamic
resource route allocation, special control
protocols for network management, scalable
signaling capabilities, bandwidth on demand,
wavelength rental, wavelength wholesale,
differentiated services for various of QOS
levels.

16. 16
Ultra – Long Haul Optical
Transmission
• Limitations imposed due to imperfections in
the transmission medium overcome.
• Cancellation of dispersion effects.
• Utilization of potential benefits of soliton
propagation.
• More understanding of interaction between
electromagnetic light wave and the
transmission medium necessary.
• Move towards infrastructure with most
favorable conditions for light propagation.

17. 17
Polymer Optic Fibers
• As transmission media.
• Easy and less expensive processing of
optical signals.
• More flexible for plug interconnections.
• May displace copper cables for last mile
connection from the telecommunication
company’s last distribution box and the
served end consumer.
• Use of Polymer Optical Fibers (multimedia
fibers) for future aircraft applications.

18. 18
Improvements in Laser Technology
• Extension of present semiconductor lasers
to a wider variety of lasing wavelengths.
• Shorter wavelength lasers with very high
output powers of interest in high density
optical applications.
• Laser sources spectrally shaped through
chirp management presently used to
compensate for chromatic dispersion.

19. 19
Improvements in Laser Technology
• Chirp management - laser controlled such
that it undergoes sudden change in its
wavelength when firing a pulse, chromatic
dispersion of the pulse reduced.
• Need to develop instruments to be used to
characterize such lasers.
• Single mode tunable lasers for future
coherent optical systems.
• Need for tuning lasers to a range of
different frequencies.

20. 20
Laser Neural Network Nodes
• Effective option realization of optical
network nodes.
• Dedicated hardware configuration working
in optical domain and the use of ultra-fast
photonic sections expected to further
improve the capacity and speed of
telecommunication networks .
• Use of optical laser neural nodes an
effective solution.

21. 21
High – Altitude Platforms
• Optical inter satellite links and orbit-to-
ground links suffer from unfavorable
weather conditions.
• Need for optical communication to and
from high altitude platforms.
• High altitude platforms - airships situated
above clouds at heights of 16 to 25 Km.
• Unfavorable atmospheric impact on laser
beam less severe than directly above
ground.

22. 22
High – Altitude Platforms
• Optical links between high- altitude
platforms, satellites and ground stations
to serve as broadband back-haul
communication channels.
• High-altitude platform to serve as data
relay stations.

23. 23
Improvements in Optical
Transmitter/Receiver Technology
• Need to achieve high quality transmission
even for optical signals with distorted
waveform and low signal to noise ratio.
• Need for optical transceivers adopting new
and advanced modulation technology, with
excellent chromatic dispersion & Optical
Signal to Noise Ratio tolerance.
• Suitability for ultra-long haul communication
systems.
• Need for better, efficient error correction
codes.

24. 24
Improvement in Optical
Amplification Technology
• Need for better technologies to enhance
EDFA performance.
• Need for high accuracy optical amplifiers to
increase gain bandwidth of EDFA, better
gain equalization technology.
• To achieve higher output power, lower noise
figure.
• Need for high power pumping lasers with
excellent optical amplification and outputs
of more than +20 dBm with very low noise
figure.

25. 25
Improvement in WDM Technology
• To extend wavelength range over which
wave division multiplexing systems can
operate.
• C band ranges from 1.53 - 1.57μm.
• Dry fiber has a low loss window, promises
extension of the range to 1.30 – 1.65 μm.
• Need for further developments in optical
filtering technology for WDM.

26. 26
Advancement in Network Configuration
of Optical Submarine Systems
• To improve the flexibility of network
configuration in optical submarine
communication systems.
• Most large scale optical submarine
systems adopt ring configuration.
• Need for mesh network configuration that
directly inter-connects the stations.
• Mesh network connects stations directly.

27. 27
Improvements in Glass Fiber Design
and Component Miniaturization
• Impurities added/removed from glass fibers
change its light transmission characteristics.
• Speed of light along a glass fiber can be
controlled.
• Allows for production of customized glass
fibers to meet specific traffic engineering
requirements of a given route.
• Need to produce more reliable and effective
glass fibers.
• Miniaturization of optical fiber communication
components.

28. 28
Exciting Optical Communication
Technologies
 Radio over Fiber:
• Analog optical link to transmit modulated
RF signals.
• Uses optical fiber links to distribute RF
signals from a central location to remote
antenna units.
• Transmits RF signal downlink and uplink.
• Transmits RF signal to central station (CS)
from base station (BS) and vice versa.

29. 29
Radio over Fiber Advantages
• Large bandwidth.
• Immunity to radio frequency interference.
• Reduced power consumption.
• Multi-operator and multi-service operation.
• Dynamic resource allocation.
• Supports video on demand, internet
usage, voice over IP, steaming video and
voice.

30. 30
Radio over Fiber Applications
• Video Distribution Systems – large
bandwidth.
• Satellite Control – Control of remote
antenna located at satellite earth station.
• Cellular Networks – enhances capacity.
• Mobile Broadband Services.
• Vehicle Communication – traffic control by
deploying base stations (BS) along roads,
BSs communicate with moving vehicles
through microwave signals.

31. 31
General Radio over Fiber System
.

32. 32
Exciting Optical Communication
Technologies
 Nanomechanical Optical Fiber:
• Multiple fiber cores capable of controlled
nanometer-scale mechanical movements.
• Cores close enough to each other to be
optically coupled, as directional coupler.
• Optical switching, sensing and WDM
applications.

33. 33
Exciting Optical Communication
Technologies
 Silicon Core Optical Fiber:
• Attenuation of 4.3 dB/m at 2.936 μm
wavelength.
• High thermal conductivity, high optical
damage threshold, and low loss
transmission between ~1.2 – 6.6 μm
of crystalline silicon beneficial.

34. 34
Silicon Core Optical Fiber
• Tremendous potential for:
- Raman and other nonlinear optical fiber
devices.
- mid- and long-wave infrared sensing
and power delivery.
- terahertz guided wave structures.

35. 35
Exciting Optical Communication
Technologies
 Li-Fi & Visible Light Communications:
• The term Li-Fi coined by Harold Hass in
2011.
• High speed bi-directional fully connected
visible light wireless communication
system.
• Not sensitive to electromagnetic
interference.

36. 36
Li-Fi and VLC
• Speed up to 10 Gb/s using Li-Fi, 250 times
more than the speed of super-fast
broadband.
• Applications such as:
- Transmitting sound and music.
- In Wireless LAN.
- Visible light ID system in subways,
hospitals and airports.

37. 37
Li-Fi and VLC
- Vehicle to vehicle communications.
- Underwater communications
eg; Un-Tethered Remotely Operated
Vehicle (UTROV).
- In signboards to convey information in
public places.
- Robotics.

38. 38
VLC for Safety Messaging

39. 39
VLC for HOSPI Robot

40. 40
Exciting Optical Communication
Technologies
• Inter-Aircraft Optical Communications:

41. 41
Conclusion
• “Further work to be done to support the
need for faster data rates, advanced
switching techniques and more intelligent
network architectures that automatically
change in response to traffic patterns and
at the same time be cost efficient”.

42. 42
Thank You