Fiber Optics

H.R.H. THE PRINCE OF WALES INSTITUTE OF ENGINEERING & TECHONOLOGYR.Bhuyan Aaditya Shyam Thowmong P. Goswami POW/11/EL/001CONTENTIntroductionHistoryWhat are Fiber OpticsFiber OpticsFiber TechnologyFiber Has More CapacityWhy Use Fiber OpticsHow Does an Optical Fiber Transmit LightAdvantages of Fiber OpticsDense Wave-Division Multiplexing (DWDM)How Are Optical Fibers MadeOptical Fiber Capacity Growth 1983-2012Fiber Optic ApplicationsConclusionReference IntroductionYou hear about fiber-optic cables whenever people talk about the telephone system, the cable TV system or the Internet. Fiber-optic lines are strands of optically pure glass as thin as a human hair that carry digital information over long distances.

HISTORYThe first commercial fiber optic installation was in for telephone signals in Chicago, installed in 1976. The first long distance networks were operational in the early 1980s. By 1985, most of today's basic technology was developed and being installed in the fiber optic networks that now handle virtually all long distance telecommunications.Concept a century oldUsed commercially for last 25 years

What are Fiber Optics? Fiber optics (optical fibers) are long, thin strands of very pure glass about the diameter of a human hair. They are arranged in bundles called optical cables and used to transmit light signals over long distances. If you look closely at a single optical fiber, you will see that it has the following parts: Core Cladding Buffer coating

Fiber Optics:-

Buffer coating claddingfiber core

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Fiber TechnologyOptical fiber is comprised of a light carrying core surrounded by a cladding (usually fused silica glass) which traps the light in the core by the principle of total internal reflection. Most optical fibers are made of glass, although some are made of plastic. The core and cladding are usually fused silica glass which is covered by a plastic coating called the buffer or primary buffer coating which protects the glass fiber from physical damage and moisture. There are some all plastic fibers used for specific applications. Glass optical fibers are the most common type used in communication applications.

Why Fiber ?That tiny strand of optical fiber can carry more communications signals than the giant copper cable in the background and over much longer distances. The copper cable has about 1000 pairs of conductors. Each pair can only carry about 24 telephone conversations a distance of less than 3 miles.The cost of transmitting a single phone conversation over fiber optics is only about 1% the cost of transmitting it over copper wire! Thats why fiber is the exclusive medium for long distance communications.

Why Use Fiber Optics?EconomicsSpeedDistanceWeight/sizeFreedom from interferenceElectrical isolationSecurity

How Does an Optical Fiber Transmit Light? Suppose we want to shine a flashlight beam down a long, straight hallway. Just point the beam straight down the hallway -- light travels in straight lines, so it is no problem. What if the hallway has a bend in it? You could place a mirror at the bend to reflect the light beam around the corner. What if the hallway is very winding with multiple bends? You might line the walls with mirrors and angle the beam so that it bounces from side-to-side all along the hallway. This is exactly what happens in an optical fiber.

How Does an Optical Fiber Transmit Light? The light in a fiber-optic cable travels through the core (hallway) by constantly bouncing from the cladding (mirror-lined walls), a principle called total internal reflection. Because the cladding does not absorb any light from the core, the light wave can travel great distances. However, some of the light signal degrades within the fiber, mostly due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light

How Does an Optical Fiber Transmit Light?

TOTAL INTERNAL REFLECTION

Fiber Optic Cables

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Advantages of Fiber OpticsHigher carrying capacityNon-flammable, and immune to lightning. Lightweight & Impossible to tap into a fiber optics cable, making it more secure.Unlike electrical signals in copper wires, light signals from one fiber do not interfere with those of other fibers in the same cableFlexible Medical imaging- in bronchoscopes, endoscopes, laparoscopes Mechanical imaging - inspecting mechanical welds in pipes and engines (in airplanes, rockets, space shuttles, cars) Plumbing - to inspect sewer lines

Dis-advantages of Fiber OpticsFiber optics are that the cables are expensive to install. The termination of a fiber optics cable is complex and requires special tools.They are more fragile than coaxial cable.Optical fiber can not be join together as easily as copper cable. It requires training and expensive splicing and measurement equipment.

Dense Wave-Division Multiplexing (DWDM)

Multiple colors (frequencies) sentthrough the fiber at the same time,more than 100

Each color carries a separate signal

Allows huge bandwidth

How Are Optical Fibers Made?Making optical fibers requires the following steps: Making a perform glass cylinder Drawing the fibers from the performTesting the fibers

Optical Fiber Capacity Growth 1983-2012 0198319841985198619871988198919901991199219931994199519961997199819992004006008001,0001,2001,400OC-48OC-192OC-192, 2lOC-48, 40lOC-192, 16lOC-48, 96lOC-192, 32lOC-192, 48lOC-192, 80lOC-192, 128l1.7 Gb565Mb135MbSingleFiberCapacity(Gigabits/sec)1 Terabit =World record 16TB per second

Fiber Optic ApplicationsFiber is already used in:> 90% of all long distance telephony> 50% of all local telephonyBecoming popular for FTTH (fiber to the home)Most CATV networksMost LAN (computer network) backbonesMany video surveillance links

19About the only places fiber has not become the dominant medium is to the home and desktop connections for LANs. That is changing. Priced to just replace copper, it is more expensive for LANs at speeds up to 1 Gb/s, but using a centralized fiber architecture, even at lower speeds, fiber allows the removal of electronics from the telecom room and ends up being less expensive. For FTTH, fiber is the only means to offer advanced services like IPTV, TV delivered over the Internet.

FOTM, Chapter 2, DVVC, Chapter 10

Trends in indiaTheNational Optical Fiber Network(NOFN) is a project to provide broadband connectivity to over two lakh (200,000)Gram panchayatsofIndiaat a cost of Rs.20,000 crore ($4 billion). 16 States and Union Territories signed the MoUs on 26 October 2012. These states and Union Territories were Andhra Pradesh, Arunachal Pradesh, Chhattisgarh, Jharkhand, Karnataka, Manipur, Mizoram, Rajasthan, Tripura, Uttar Pradesh, Uttarakhand and 3 Union Territories viz. Dadra & Nagar Haveli, Daman & Diu and Puducherry.. Tripartite MoU were signed with other ten states and Union Territories on 12 April 2013. These states and Union Territories were Assam, Bihar, Gujarat, Himachal Pradesh, Jammu & Kashmir, Maharashtra, Nagaland, Odisha, Punjab and Andaman & Nicobar Islands. In these states and Union Territories, overall 85731 gram panchayaths will get covered by Optical Fibre Network.

FUTURE EXTENSIONLong lastingFlexibility

Jobs In Fiber OpticsDesigning componentsManufacturing fiber, lasers, etc.Designing systemsInstalling cabling and networksTraining and teaching

22There are lots of jobs available in fiber optics. Each has unique requirements and requires different educational backgrounds.Designers:Most of those who design components have at least a undergraduate degree. For components like connectors, it would be in mechanical engineering. Optical components like fibers require knowledge of both optics and materials, so many designers will have degrees in physics, chemistry or materials.If you want to develop lasers or photodetectors, you should have a background in solid-state physics.Manufacturing jobs will have differing requirements depending on the technical nature of the job. Some require manual skills while others may require advanced technical education to understand the complicated manufacturing processes.Designers of fiber optic systems are usually electronic engineers. Fiber optic components are used like integrated circuits to develop communications systems.Installers must be skilled in the process of pulling cables, then splicing and terminating them. It requires more manual dexterity than the other jobs, plus a basic understanding of how the systems work.

Conclusion In several ways fiber optics is a pivotal breakthrough from the electric communication we have been accustomed to. Instead of electrons moving back and forth over a regular copper or metallic wire to carry signals, light waves navigate tiny fibers of glass or plastic to accomplish the same purpose.With a bandwidth and information capacity a thousand times greater than that of copper circuits, fiber optics may soon provide us with all the communication technology we could want in a lifetime, at a cost efficient price. Referenceshttp://electronics.howstuffworks.com/fiber-optic7.htmhttp://www.commspecial.com/fiberguide.htmhttp://www.thefoa.org/http://www.fiber-optics.info/fiber-history.htm