1. Introduction to Fiber Optics
Presented by: James Carter
Sales Engineer – Cox Business

2. Scope This presentation is designed to give a general
overview of fiber optic theory, its construction,
the two basic types of fibers, and the benefits
of fiber networks over traditional copper based
networks.

3. Content Terms Definition Quick history Wavelengths of light
Anatomy of a fiber
Types of fiber
Model of a simple fiber optic link
Benefits over copper-based networks
Fiber optic applications
CATV applications

4. Terms Attenuation: Attenuation is a general term that refers to
any reduction in the strength of a signal.
Bandwidth: The amount of data that can be passed along a
communication medium in a given period of time.
Decibel (dB): A unit used to express the difference in intensity,
usually between two acoustic, light, or electrical signals. In fiber
optics, the decibel is combined with the kilometer (dB/km) to form
the unit for measuring attenuation (signal loss) in a section of fiber.
Electromagnetic Spectrum (EMS): This is a term that scientists
use when they want to talk about the vast range of energy
that radiates in every corner of the universe.

5. Terms - cont.
Electromagnetic Interference (EMI): A disturbance that affects
electrical circuits. It can degrade AM/FM radios, cell phones,
television reception…. It can occur naturally – sun flares, or
artificially. Any electronic device ever invented has the potential
to generate interference.
Fiber-to-the-X (FTTX): A catch all acronym for all of the variations
on the use of fiber between the service and the customer. These
Include fiber-to-the-node (FTTN), fiber-to-the-curb (FTTC), fiber-to-
the-home (FTTH), and fiber-to-the-premise (FTTP).
Kilo (k): A prefix in the International System of Units denoting the
number For example, a kilometer = 1000 meters.

6. Terms – cont.
Local Area Network (LAN): A local area network is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport.
LASER: A laser is a device that emits light through a process called stimulated emission. In communication networks, a LASER is used
to convert electrical signals (radio frequencies), into light signals.
Master Telecommunications Center (MTC): The central location where Cox Communications, acquires and combines, all the
services that are offered to our customers. The MTC is also
known as a “headend”.
Metropolitan Area Network (MAN): A large LAN that typically can
span up to 50km.

7. Terms – cont.
Micron (μ): A unit of length equal to one millionth of a meter.
Nano (n): A unit of length equal to one billionth of a meter. It is
commonly used in fiber optics to differentiate between the various wavelengths of light. For example, the color blue has a wavelength of 475 nanometers.
Optical receiver: In communication networks, it is the device that
receives the light signals from a LASER and converts the light
signals back to electrical signals (radio frequencies).

8. Terms – cont.
Radio frequencies (RF): That part of the vast electromagnetic spectrum
that can be harnessed for such purposes as

9. Terms – cont Secondary Telecommunications Center (STC): The STC is a
smaller version of the MTC. The STC is also referred to as a “hub”.
Wide Area Network (WAN): Whereas a LAN (local area network) is a network that links computers, printers and other devices located in an office, a building or even a campus , a WAN (wide area network) is a system that extends for greater distances and is used to connect LANs (local area networks) together. A WAN can encompass
networks across a state, the country as a whole, or the world.

10. Definition
An optical fiber is a glass or plastic strand that can carry information -
in the form of light, along its length. Optical fibers are widely used in
communications because they permit transmissions over longer
distances and at higher bandwidths (data rates) than traditional copper-
based networks.
With very low attenuation ( signal loss), immunity from all electrical
interference, and high bandwidth capacity, optical fibers are almost
the perfect medium for communications.

11. Quick History Though the use of fiber optics is common in modern
communication networks, the
guiding of light through a clear
medium is a fairly simple concept.
Using a container of water, and a
simple light source, Daniel Colladon
and Jacques Babinet demonstrated
the guiding of light in Paris in the
early 1840s.
Light
source
Water
reservoir
Light carried
by water
stream

12. Quick History – cont.
In more modern times, scientists worked on developing a fiber so pure that
when a light source was introduced at one end, after a distance of one
kilometer, one per cent of the light remained. In terms of attenuation (signal
loss), this was equal to 20 decibels – the existing transmission distance for a
copper-based telephone system.
The crucial attenuation level of 20 decibel per kilometer was first achieved in
1970 by Drs. Robert Maurer, Donald Beck, and Peter Schultz, of glass maker Corning
Incorporated. They demonstrated a fiber with an attenuation of 17dB/km.
A few years later they produced a fiber with an attenuation of only 4dB/km. This
enabled General Telephone & Electronics to sent the first live telephone traffic
on April 22, 1977, in Long Beach, California.
Today, the purity of glass enables attenuation levels of 1310nm, and
1550nm. Combined with improvements in LASERs, optical receivers,
and other optical components, optical networks can transmit digitized signals long
distances – in many cases without the need of optical amplifiers.

13. Wavelengths of light
You may not be aware of it, but the electromagnetic
spectrum is quite familiar to you: The microwave
you heat your food with, the cell phone you keep in
touch with, your favorite television show, the light from
the sun that both warms and burns, plus the light your eyes
use to see; it is all part of the electromagnetic spectrum.

14. Wavelengths of light – cont.
Visible light:
650nm
400
700
Light not visible to the naked eye:
wavelength
1310 nm
1550 nm

15. Anatomy of an optical fiber
Three functional components:
Core
Silica glass with Germania
Purpose – signal transmission
Cladding
Silica glass
Purpose – signal containment
Coating
Dual-layer, UV cured acrylate
Purpose – mechanical protection

16. Types of fibers Putting the micron (μ) in perspective
A human red blood cell is 10 microns across.
A human hair ranges from 40 – 120 microns wide.
The period at the end of this sentence is about 397 microns.
The eye of a typical needle is 749 microns wide.
A postage stamp 25,400 microns long.

17. Types of fibers – cont. 50 & 62.5 microns Cladding 125 microns Plastic
Coating
250 microns
Multimode
8 – 10 microns
125μm μm
Single-mode

18. Types of fibers – cont. Multimode fibers Disadvantages Advantages
Optimized for distances
less than 2Km
Higher attenuation than
single-mode fiber
Multimode fibers
Advantages
Uses inexpensive light sources
Uses low cost connectors
that are easy to install
Easier and cheaper to install
Works well for LAN,
college campus networks
Easier to splice when cut
Can handle high data rates

19. Types of fibers – cont. Single-mode fiber Disadvantages
Uses expensive LASERs
as a light source
Difficult to install connectors
Higher installation costs
More susceptible to damage
during installation
More difficult to splice when
cut
Advantages
Optimized for long
haul applications
Very low attenuation
Light can reach distances
50 miles without the
need of optical amplifiers
Can handle high data rates

20. Types of fibers – cont. Attenuation: Single-mode vs. Multimode

21. Types of fibers – cont. Single bare fiber
250μm
Single bare fiber
900μm
Single fiber strand with additional
white plastic coating

22. Types of fibers – cont. Up to 432 fibers for Fiber glass support
Buffer tubes
Rip cord
Individual fibers
Armor
Mylar wrap
Plastic
Up to 432 fibers for
single-mode cable

23. Fiber optic link Model of "simple" fiber optic data link fiber
Information
Source
Optical
Receiver
Information
To Customer
LASER
Model of "simple" fiber optic data link

24. Benefits vs. traditional networks
Not susceptible to electro-
magnetic or other types of
electrical interference
Not affected by temperature
No amplification required up to
@ 50 miles
Greater information carrying capacity
Lightweight
More secure
Less attenuation than copper-
based cables
Improved quality of the signals
transmitted

25. Benefits vs. traditional networks - cont.
Why use fiber?
Capacity of 2400 pair copper telephone cable:
- 1 call per copper pair
Capacity of a single fiber:
- > 500,000 calls
Size and weight
To transmit equivalent information 1 mile
Single fiber cable =28 lbs
Equivalent capacity copper cable = 33 tons

26. Fiber optic applications
LAN B A
Access
Metro
Long Haul
-WAN
-Cross-country/Intercontinent
-Submarine
>200 km
MAN/city rings km
Fiber-to-the-X
(curb, building, home)
0-10 km
LAN
0-2 km

27. Cable applications Cable Networks MTC Tree-and-Branch Microwave
Service
Area
                                                                       
Long cascade of amplifiers
Service
Area
Microwave
HUB
Hybrid-Fiber-Coaxial
Service
Area

28. Cable applications – cont.
Ring-in-ring HFC Network
Fiber Access Network
Fiber Transport Network
Distribution Amplifier
Line Extender Amplifier
Coaxial Access Network
MTC
Hub/STC