presentation fiber

7/31/2019 Presentation fiber

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FIBER OPTICS

GROUP MEMBER:

MUHAMAD FADLILAH BIN MUKHLAS

KU MOHD SYAFIQ B KU YUSOFF

MOHD AIDIL UBAIDILLAH B RAZILAN

SUARDI B NANANG



INTRODUCTION

• An optical fiber (or optical fibre) is a flexible,

transparent fiber made of a pure glass (silica) not

much wider than a human hair.

• Optical fiber typically includes of a transparent

core surrounded by a transparent cladding

material with a lower index of refraction

• Light is kept in the core by total internal reflection.

This causes the fiber to act as a waveguide.



HISTORY

• 2500 B.C- Earliest known glass

• 1790s- Claude Chappe invents 'optical telegraph' inFrance

• 1840s - Guiding of light by refraction, the principle thatmakes fiber optics possible, was first demonstratedby Daniel Colladon and Jacques Babinet in Paris

• 1920s- Image transmission through tubes wasdemonstrated independently by the radioexperimenter Clarence Hansell and the televisionpioneer John Logie Baird

• The principle was first used for internal medicalexaminations by Heinrich Lamm in the following decade

• 1954- Harold Hopkins and Narinde Singh Kapany at Imperial College in London achieved low-losslight transmission through a 75 cm long bundle whichcombined several thousand fibers

http://en.wikipedia.org/wiki/Narinder_Singh_Kapany






HISTORY

• 1956- The first fiber optic semi-flexible gastroscope waspatented by Basil Hirschowitz , C. Wilbur Peters, andLawrence E. Curtiss, researchers at the University of Michigan

• 1963- Jun-ichi Nishizawa, a Japanese scientist

at TohukuUniversity, also proposed the use of opticalfibers for communications

• Nishizawa invented other technologies that contributedto the development of optical fiber communications,such as the graded-index optical fiber as a channel fortransmitting light from semiconductor lasers

• Charles K. Kao and George A. Hockham of the Britishcompany Standard Telephones and Cables (STC) werethe first to promote the idea that the attenuation inoptical fibers could be reduced below 20 decibels perkilometer (dB/km), making fibers a practicalcommunication medium



HISTORY

• NASA used fiber optics in the television cameras sent tothe moon

• 1970- The crucial attenuation limit of 20 dB/km wasfirst achieved by researchers Robert D. Maurer, DonaldKeck, Peter C. Schultz, and Frank Zimar working for

American glass maker Corning Glass Works,now Corning Incorporated

• 1981- General Electric producedfused quartz ingots that could be drawn into fiber opticstrands 25 miles (40 km) long

• 1986- The erbium-doped fiber amplifier, which reduced

the cost of long-distance fiber systems by reducing oreliminating optical-electrical-optical repeaters, was co-developed by teams led by David N. Payne of the University of Southampton and EmmanuelDesurvire at Bell Labs

• 1991- Masataka Nakazawa of NTT reports sending

soliton signals through a million kilometers of fiber.



HISTORY

• 1993- Nakazawa sends soliton signals 180 million

kilometers, claiming "soliton transmission over

unlimited distances." Linn Mollenauer of Bell Labs

sends 10 billion bits through 20,000 kilometers of fibers

using a simpler soliton system

• 1996- Fujitsu, NTT Labs, and Bell Labs all report

sending one trillion bits per second through single

optical fibers in separate experiments using different

techniques.

• 2000- The first photonic crystal fibers became

commercially available



APPLICATION IN

ELECTRONICS DEVICESTelecommunication

• An optical communication system consists of atransmitter, which encode a message into the opticalsignal, the channel, which carries these signals to thedestination, and the receiver, which reproduce the

message from the received optical signal. • Fiber optics is the most common types of channels

for optical communications, but other types of opticalwaves used in computer or communicationsequipment, and even formed a very short distance of the channel (eg, chip to chip, intra-chip) in a test lab.

• Transmitters in fiber-optic link is generally light-emitting diode or laser diode. More commonly usedinfrared light from the visible light, because opticalfibers transmit infrared waves with damping and amuch smaller dispersion.



APPLICATION IN

ELECTRONICS DEVICES



MECHANISM

Physics of Total Internal Reflection

• light passing between two media of different refractive

indexes n1 and n2

• If n1> n2 the light ray as it passes from one media to the

next will bend away from an imaginary line (the normal)

perpendicular to the media’s mating surface.

• Conversely if n1 < n2 then the ray will bend towards the

normal.

• Total internal reflection occurs when n1 > n2 and the

incident ray of light makes an angle, Θc, such that it does

not enter the adjacent medium but travels along the

interface.

• At angles greater than Θc the ray will be reflected back

into medium



MECHANISM



MECHANISM

Ray Theory

• Light enters the core of the optical fiber and strikes the

core/cladding interface at an angle Θ .

• If this angle is greater than the critical angle (i.e.Θ ≥ Θcw h

e r eΘ c= a r c s i n ( n2/n1)) then the ray will reflect back

into the core thus experiencing total internal reflection.

• This ray of light will continue to experience total internal

reflection as it encounters core/cladding interfaces while

propagating down the fiber



MECHANISM



MANUFACTURING

Materials

• Silica - Silica exhibits fairly good optical transmission overa wide range of wavelengths. In the near-infrared (near IR)portion of the spectrum, particularly around 1.5 μm, silicacan have extremely low absorption and scattering losses

of the order of 0.2 dB/km.• Fluorides - Fluoride glass is a class of non-oxide optical

quality glasses composed of fluorides of various metals.

• Phosphate - Phosphate glass constitutes a class of opticalglasses composed of metaphosphates of various metals.Phosphate glasses can be advantageous over silica glasses

for optical fibers with a high concentration of doping rareearth ions.

• Chalcogenides - These are extremely versatilecompounds, in that they can be crystalline or amorphous,metallic or semiconducting, and conductors of ions or

electrons.



MANUFACTURING

Process

• Standard optical fibers are made by first constructing a

large-diameter "preform", with a carefully controlled

refractive index profile, and then "pulling" the preform to

form the long, thin optical fiber. The preform is commonly

made by three chemical vapor deposition methods: insidevapor deposition, outside vapor, and vapor axial

deposition.



MANUFACTURING



MANUFACTURING

Coating

• The light is "guided" down the core of the fiber by an

optical "cladding" with a lower refractive index that traps

light in the core through "total internal reflection."

• The cladding is coated by a "buffer" that protects it from

moisture and physical damage.

• The buffer is what gets stripped off the fiber for

termination or splicing.

• These coatings are UV-cured urethane acrylate composite

materials applied to the outside of the fiber during the

drawing process.

• The coatings protect the very delicate strands of glass

fiber about the size of a human hair and allow it to survive

the rigors of manufacturing, proof testing, cabling and

installation.



MANUFACTURING



ADVANTAGES

Dispersion

• When the rays pass through fiber media, the

rays will take information a large amount of data

through the distance. In summary, broadband

Dispersion is the ability to carry data transmitted

/ propagated in optical fiber media.

Bandwidth

• When light propagates to use certain

frequencies. The size of the frequency used will

influence the information data capacity that

pass through the medium.



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