Optical fiber is the technology associated with data transmission using light pulses travelling along with a long fiber which is usually made of plastic or glass. Metal wires are preferred for transmission in optical fiber communication as signals travel with fewer damages. Optical fibers are also unaffected by electromagnetic interference. The fiber optical cable uses the application of total internal reflection of light. The fibers are designed such that they facilitate the propagation of light along with the optical fiber depending on the requirement of power and distance of transmission. Single-mode fiber is used for long-distance transmission, while multimode fiber is used for shorter distances. The outer cladding of these fibers needs better protection than metal wires.
1. Solapur education society
S E S POLYTECNIC , SOLAPUR
certificate
This is to certify that the following student
ROLL NO NAME
3307 Ajinkya .B. More
3311 Shridhar .V. Budharam
3316 Mahesh . A . Aldar
3306 Gopalkrishna .A.Yele
Of fifth semester of diploma in electronic and telecommunication of institute
S.E.S Polytecnic solapur (0095) have completed the micro project work on(
Different types of optical fiber cable ) satisfactorily under my supervision and
guidence in subjectin Optical Network and Satellite Communication (22647) for
the academic year 2020 – 2021 as prescribed in the above curriculum
Prof. S. M. Tipe prof. N.D.Kulkarni
(Sub. Teacher) ( HOD ) (Principal)
2. Brief flow of presentation
1. Introduction
2. What are Optical Fibers?
3. Evolution of optical fiber
4. Structure of optical fiber
5. Workings principle of optical fiber
6. What is optical fiber cable .
7. How to select proper optical fiber cable
8. Advantages and Disadvantages
9. Conclusion
3. What is optical fiber
Optical fiber is the technology associated with data transmission using light pulses
travelling along with a long fiber which is usually made of plastic or glass. Metal
wires are preferred for transmission in optical fiber communication as signals
travel with fewer damages. Optical fibers are also unaffected by electromagnetic
interference. The fiber optical cable uses the application of total internal reflection
of light. The fibers are designed such that they facilitate the propagation of light
along with the optical fiber depending on the requirement of power and distance of
transmission. Single-mode fiber is used for long-distance transmission, while
multimode fiber is used for shorter distances. The outer cladding of these fibers
needs better protection than metal wires.
Evolution of optical fiber
1880: Alexander Graham Bell invented Photophone
1948: Claude Shannon formulated the Shannon Limit of a communication
channel (Shannon, 1948)
1957: Charles Townes and Arthur Schawlow outlined principles of laser
operation (Schawlow and Townes, 1958)
1966: Charles Kao concluded that the fundamental limit on glass transparency
is below 20 decibels per kilometer, which would be practical for
communications. Hockham calculated that clad fibers should not radiate much
light. They prepared a paper proposing fiber-optic communications (Kao and
Hockham, 1966)
1970: First continuous-wave room-temperature semiconductor lasers made in
early May by Zhores Alferov's group at the Ioffe Physical Institute in
Leningrad (now St. Petersburg) and on June 1 by Mort Panish and Izuo
Hayashi at Bell Labs
1987: David Payne's group reported making the first erbium-doped optical
fiber amplifier at the University of Southampton. Emmanuel Desurvire and
Randy Giles developed a model to predict the behavior of erbium optical
amplifier at Bell Labs (Mears et al., 1987, Giles and Desurvire, 1991)
1988: Linn Mollenauer of Bell Labs demonstrated soliton transmission through
4,000 km of single-mode fiber
4. 1993: Andrew Chraplyvy et al. at Bell Labs transmitted at 10 Gb/s on each of
eight wavelengths through 280 km of dispersion-managed fiber (Chraplyvy
et al., 1993)
1996: Commercial wavelength-division multiplexing (WDM) systems were
introduced
2002: Differential phase-shift keying (DPSK) was first demonstrated for 40
Gb/s long-haul (4,000 km) transmission by Bell Labs (Xu et al., 2004, Gnauck
et al., 2002)
2002: Nonlinearity compensation in fiber transmission was introduced for
phase-modulated signals by Bell Labs (Liu et al., 2002)
2003: Gigabit-capable Passive Optical Networks (G-PON) was standardized by
the Telecommunication Standardization Sector of the International
Telecommunication Union (ITU-T)
2004: DSP-based coherent optical detection concept was introduced by
Michael Taylor of University College London (Taylor, 2004)
2009: Superchannel concept was introduced and experimentally demonstrated
at 1.2 Tb/s by Bell Labs (Chandrasekhar et al., 2009)
2010: Rene Essiambre et al. at Bell Labs studied the Shannon Limit for
nonlinear fiber-optical transmission (Essiambre et al., 2010)
2010: 10-Gigabit-capable Passive Optical Networks (XG-PON) were
standardized by ITU-T
2011: Peter Winzer et al. at Bell Labs researched spatial multiplexing for
optical transport capacity scaling (Winzer, 2011)
2012: Flexible-grid WDM was standardized by ITU-T (Recommendation ITU-
T G.694.1, 2012)
2016: Low-loss low-nonlinearity optical fibers were specified by ITU-T (Zong
et al., 2016)
2018: Low-loss M×N colorless-directionless-contentionless (CDC)
wavelength-selective switch (WSS) was developed by Lumentum (Colbourne
et al., 2018)
2019: Super-C-band transmission with 6-THz optical bandwidth was
demonstrated by Huawei Technologies (Huawei's ON2.0, 2019)
5. Structure of optical fiber cable
The general structure of optical fibers is the same for any
cable. Let’s take a look at this general build of an optical fiber.
If the words Optical fiber are a bit strange for you, just think of
them as wires that can transmit light. Consequently, these
wires are thin and flexible. They are not made of metal, like the
regular wires you see running around your house. Instead,
they are made up of special types of glass or transparent
plastic.
There are a few different types of optical fibers available in
the market. The general structure of optical fibers includes the
following three parts.
1. The Core – Yep, it is precisely what you think it is.
2. Cladding – Good guessing!
3. Jacket – Did you get this one?
6. The Core of an Optical Fiber
The core is the innermost part that is made out of glass or
transparent plastic. It is extremely thin, flexible, and has a
cylindrical shape.
Its sole purpose is to keep all the light within itself. And also to
guide the light in a direction parallel to its axis.
Since it is the primary carrier and guide of the light waves, it can
be called an optical waveguide. By the same token, its structure
affects the transmission of the light. Hence, all the data that is
being transferred will have its transmission parameters or
properties based on the structure of this segment of the fiber
optic. Makes sense.
The cladding of an optical fiber
The cladding is the second layer on top of the core. It
is also made of glass or transparent plastic. But with a
different material, so the refractive index of the cladding
is lower than that of the core.
To understand the need for a secondary layer made out of
a different material, we will revisit a basic concept of light
propagation from the ray theory of light: refraction
When light from a medium with a high refractive index goes to
a medium with a low refractive index, it moves away from the
normal at the point of crossover. Take a look at the image
below. The red line runs away from the normal as it enters the
cladding, which has a lower refractive index. Can you now
think of a reason as to why this would be necessary? We will
get to that in a subsequent article. Hint: It has got something
to do with efficiency.
7. As a matter of fact, the cladding is not essential for light
propagation. But it increases efficiency and reduces
scattering losses in addition to providing mechanical
strength. So we might as well as use it!
The jacket of an optical fiber
The jacket exists purely for protecting the core and the
cladding.
It is made up of flexible and abrasion-resistant varieties of
plastic.
Usually, the jacket has another layer beneath it called a
buffer.
The buffer and the jacket together protect the optical fiber
from environmental and physical damage.
These three parts are common to all types of cables and make
up the general structure of optical fibers. Please note that there
are many applications of optical fibers like a fiberscope, which
allows you to see difficult to reach places, fiber optic sensors,
which enable you to measure some physical quantity, and so
on. Henceforth and throughout this course, we will be
discussing optical fibers that are used for communication
purposes.
8. Working of Optical Fiber
The working principle of optical fiber is the transmission of
the information in the form of light atoms otherwise photons.
The cores of the fiberglass & the cladding have a special
refractive index to twist inward light at a particular angle.
Whenever light gestures are transmitted through the optical
cable, then they do not reflect the cladding & core within a
sequence of zigzag bounces, sticking to a method is named as
total internal reflection
An optical fiber is a lengthy, thin thread of plain material. The
shape of this cable is similar to a cylinder. The core of this
cable is located in the center, and the outside of the core is
named as cladding. Here cladding works like a protective layer.
These two are made with different types of plastic otherwise
glass. So the traveling of light in the core can be very slow then
transmits into the cladding.
When the light within the core strikes the border of the
cladding in a less than 90oangle, then it bounces off. No light
run away until it approaches the fiber end if not, the fiber is
twisted sharply or extended. The cladding of the cable can be
damaged once it gets scratch. So, a plastic coating like buffer
protects the cladding. This buffered fiber can be located in a
tough layer, which is known as the jacket. So the fiber can be
used easily without damaging it.
9. What Is Fiber Optic Cable?
All fiber optic cable types are comprised of a core that transmits
light, generally either glass or plastic, a cladding which reflects
that light to prevent loss, and surrounded by sheathing meant to
protect the core and cladding from damage. The thickness of
these layers can vary, depending on where the cable will be
placed and what kind of performance is needed. So, what are the
different types of fiber optic cables?
10. Single-mode
SIngle-modefiberoptic cable excels at long-distance communication.
Single-mode cable is designed to carry a single signal source with low
transmission loss over great distances.It is frequently used for
communication systems due to the clarity it provides. This type of fiber
optic cable has the smallest core and the thickest sheathing.
Multimode
Multimode cables are designed to carry multiple signals, however, this
capacity comes with a loss of range. Multimode cables come in two primary
varieties. What are the differenttypes of multimode fiberoptic cables? Your
choices are step index or graded index cables.
Step indexmultimode cables have a thick core through which signals are
fed.They work well over moderate distances and can offerlonger range
communication potential with the use of amplifiers.The various light signals
enter at differentangles, transmitting at differentrates through the cable.
11. Graded index multimode cables
have a core arranged in concentric circles,like the cross section of a tree.
As light enters, it is transmitted through the rings with the outer rings
travelling faster than transmissions in the central core. This type of cable
can handle many wavelengths of light at once, making it perfectforclear
communication and data transfer requiring up to 100Gb transfer rate, as
you would find at a large data center.
How to Select the Right Optical Fiber Cable?
Optical fiber cable has gained much momentum in communication networks, and
there emerges a dazzling array of vendors competing to manufacture and supply
fiber optic cables. When selecting optical fiber, you’d better start with a reliable
vendor and then consider the selection criteria. Here’s a guide to clarify some of
the confusions about choosing fiber optic cable.
Check Manufacturer Qualification
The major optical cable manufacturers should be granted ISO9001 quality system
certification, ISO4001 international environment system certification, the ROHS,
the relevant national and international institutions certification such as the
Ministry of Information Industry, UL certification and etc.
Fiber Mode: Single Mode or Multimode
As illustrated above, single mode fiber is often used for long distances while
multimode optical fiber is commonly used for short range. Moreover, the system
12. cost and installation cost change with different fiber modes. You can refer to Single
Mode vs Multimode Fiber: What’s the Difference? and then decide which fiber
mode you need.
Optical Cable Jackets: OFNR, OFNP, or LSZH
The standard jacket type of optical cable is OFNR, which stands for “Optical Fiber
Non-conductive Riser”. Besides, optical fibers are also available with OFNP, or
plenum jackets, which are suitable for use in plenum environments such as drop-
ceilings or raised floors. Another jacket option is LSZH. Short for “Low Smoke Zero
Halogen”, it is made from special compounds which give off very little smoke and
no toxic when put on fire. So always refer to the local fire code authority to clarify
the installation requirement before choosing the jacke t type.
Optical Fiber Internal Construction: Tight Pack or
Breakout or Assembly or Loose Tube
Tight pack cables are also known as distribution style cables, features that all
buffered fibers under a single jacket with strength members for Enclosure to
Enclosure and Conduit under Grade installations. Breakout fiber cable or fan out
cable is applicable for Device to Device applications with tough and durable
advantages. Assembly or zip cord construction is often used for making optic
patch cables and short breakout runs. While loose tube construction is a Telco
standard used in the telecommunications industry.
Indoor vs. Outdoor
The choice greatly depends on your application. The major difference between indoor and
outdoor fiber cable is water blocking feature. Outdoor cables are designed to protect the
fibers from years of exposure to moisture. However, nowadays there have been cables with
both dry water-blocked outdoor feature and indoor designs. For example, in a campus
13. environment, you can get cables with two jackets: an outer PE jacket that withstands
moisture and an inner PVC jacket that is UL-rated for fire retardancy.
Fiber Count
Both indoor and outdoor fiber cable have a vast option of fiber count ranging from 4-144
fibers. If your fiber demand exceeds this range, you can custom the fiber count for indoor or
outdoor optical cable. Unless you are making fiber patch cords or hooking up a simple link
with two fibers, it is highly recommended to get some spare fibers.
14. Advantages of Optical Fiber
Greater bandwidth & faster speed—Optical fiber cable supports extremely high
bandwidth and speed. The large amount of information that can be transmitted
per unit of optical fiber cable is its most significant advantage.
Cheap—Long, continuous miles of optical fiber cable can be made cheaper than
equivalent lengths of copper wire. With numerous vendors swarm to compete for
the market share, optical cable price would sure to drop.
Thinner and light-weighted—Optical fiber is thinner, and can be drawn to
smaller diameters than copper wire. They are of smaller size and light weight than
a comparable copper wire cable, offering a better fit for places where space is a
concern.
Higher carrying capacity—Because optical fibers are much thinner than copper
wires, more fibers can be bundled into a given-diameter cable. This allows more
phone lines to go over the same cable or more channels to come through the cable
into your cable TV box.
Less signal degradation—The loss of signal in optical fiber is less than that in
copper wire.
Light signals—Unlike electrical signals transmitted in copper wires, light signals
from one fiber do not interfere with those of other fibers in the same fiber cable.
This means clearer phone conversations or TV reception.
Long lifespan—Optical fibers usually have a longer life cycle for over 100 years.
Disadvantages of Optical Fiber
Low power—Light emitting sources are limited to low power. Although high power
emitters are available to improve power supply, it would add extra cost.
Fragility—Optical fiber is rather fragile and more vulnerable to damage compared
to copper wires. You’d better not to twist or bend fiber optic cables too tightly.
15. Distance—The distance between the transmitter and receiver should keep short or
repeaters are needed to boost the signal.
Conclusion
Optical fiber provides a fast, constant and stable Internet connection that allows a lot of data
to be transmitted over incredible distances. As data demands become enormous, fiber optic
cabling is the sure way to go for network flexibility and stability.