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8/3/2019 nikhil pptf
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Laser &Laser & OpticalOpticalFibersFibers
Prepared by :Prepared by : Nikhil KumarNikhil Kumar
M.TechM.Tech in Laser Technologyin Laser TechnologyRoll noRoll no--001131201006001131201006
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ContentsContents
Fiber LaserFiber Laser
Advantages of Fiber LaserAdvantages of Fiber Laser
Disadvantages of Fiber LaserDisadvantages of Fiber Laser
Design and manufactureDesign and manufacture Fiber Disk LasersFiber Disk Lasers
Optical fibersOptical fibers
Use
ofOptical
fibersUse
ofOptical
fibers
Advantages of Optical fibersAdvantages of Optical fibers
Disadvantages of Optical fibersDisadvantages of Optical fibers
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Fiber LaserFiber LaserAA fiberfiber laserlaser is a laser in which the active gainis a laser in which the active gainmedium is anoptical fiber doped with raremedium is anoptical fiber doped with rare--earthearthelements such as erbium,elements such as erbium, ytterbiumytterbium and thulium.and thulium.They are related to doped fiber amplifiers, whichThey are related to doped fiber amplifiers, whichprovide light amplification without lasing. Fiberprovide light amplification without lasing. Fiber
nonlinearities, such as stimulated Ramannonlinearities, such as stimulated Ramanscattering orfourscattering orfour--wave mixing can also providewave mixing can also provide
gain and thus serve as gain media for a fiber laser.gain and thus serve as gain media for a fiber laser.
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Advantages ofFiber LaserAdvantages ofFiber Laser
High Power: ease ofcooling in long fiberHigh Power: ease ofcooling in long fiberHigh Stability: spliced wave guiding fibersHigh Stability: spliced wave guiding fibers
High Reliability: operate 24/7 for decadesHigh Reliability: operate 24/7 for decades
Lower total cost ofownershipLower total cost ofownership
Low jitter and low amplitude noiseLow jitter and low amplitude noise
Compact form factorCompact form factorImmune to tough environmental changesImmune to tough environmental changes
TurnTurn--key Operationkey Operation
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Disadvantages ofFiberDisadvantages ofFiber
LaserLaserPulse pedestals from non-ideal optical
spectrum for higher energy pulses.
Undesired nonlinearoptical effects at high
pulse energy, such as self-phase modulation
and Raman scattering.
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Design & ManufactureDesign & Manufacture
Unlike most other types of lasers, the laser cavity infiber lasers is constructed monolithically by fusionsplicing different types offiber ; fiber Bragggratings replace conventional dielectric mirrors to
provide optical feedback. Another type is thesingle longitudinal mode operationofultra narrowdistributed feedback lasers where a phase-shiftedBragg grating overlap the gain medium. Fiberlasers are pumped by semiconductor laser diodesor by otherfiber lasers.
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Power ScalingPower ScalingRecent developments infiber laser technology
have led to a rapid and large rise in achieveddiffraction-limited beam powers from diode-pumped solid-state lasers. Due to theintroductionof large mode area (LMA) fibersas well as continuing advances in high powerand high brightness diodes, continuous-wavesingle-transverse-mode powers from Yb-doped
fiber lasers have increased from 100 W in 2001to >50 kW. Single mode lasers have reached10 kW inCW power .
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Fiber disk lasersFiber disk lasers
Another type offiber laser is the fiber disk laser.
In such, the pump is not confined within the
cladding of the fiber (as in the double-cladfiber), but pump light is delivered across the
core multiple times because the core is coiled
on itself like a rope. This configuration issuitable for power scaling in which many
pump sources are used around the periphery of
the coil.
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Optical FiberOptical Fiber
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Optical FiberOptical Fiber
Anoptical fiber is a flexible, transparent fiber madeofvery pure glass (silica) not much wider than a
human hair that acts as a waveguide, or "light
pipe", to transmit light between the two ends of thefiber . Optical fiber typically consists ofa
transparent core surrounded by a transparentcladding material with a lower index of refraction.Light is kept in the core by total internal reflection.
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Uses of Optical FibersUses of Optical Fibers
Opticalfibers
offer huge c
ommu
nicati
oncapacity. A single fiber can carry the
conversations ofevery man, woman and childon the face of this planet, at the same time,twice over. The latest generations ofopticaltransmission systems are beginning to exploit asignificant part of this huge capacity, to satisfythe rapidly growing demand for datacommunications and the Internet.
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Advantages of Optical FibersAdvantages of Optical Fibers
CapacityCapacity
Size and Weight
Running Costs
Security
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CapacityCapacityOptical fibers carry signals with much less energy loss
than copper cable and with a much higher
bandwidth . This means that fibers can carry more
channels of informationover longer distances andwith fewer repeaters required.
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Size and WeightSize and Weight
Optical fiber cables are much lighter and thinnerOptical fiber cables are much lighter and thinner
than copper cables with the same bandwidth. Thisthan copper cables with the same bandwidth. This
means that much less space is required inmeans that much less space is required in
underground cabling ducts. Also they are easierforunderground cabling ducts. Also they are easierfor
installation engineers to handleinstallation engineers to handle..
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SecuritySecurity
Optical fibers are much more difficult to tapinformationfrom undetected; a great advantage for
banks and security installations. They are immune to
Electromagnetic interference from radio signals, carignition systems, lightning etc. They can be routed
safely through explosive orflammable atmospheres,
for example, in the petrochemical industries or
munitions sites, without any riskof ignition.
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Running CostsRunning Costs
The main consideration in choosing fiber wheninstalling domestic cable TV networks is the
electric bill. Although copper coaxial cable can
handle the bandwidth requirement over the shortdistances ofa housing scheme, a copper system
consumes far more electrical power thanfibre,
simply to carry the signals.
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Disadvantages of Optical fiberDisadvantages of Optical fiber1. Enormous Bandwidths
2. Low transmission loss
3. Immunity to cross talk
4. Small size and weight
5. Signal security
6. Electrical Isolation
7. Ruggedness and flexibility
8. Low cost and availability9. Reliability
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Thank youThank you