Fiber Joints Fibers must be joined when Fibers must be joined when You need more length than you can...

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Fiber Joints Fiber Joints Fibers must be joined when Fibers must be joined when You need more length than you can You need more length than you can get on a single roll get on a single roll Connecting distribution cable to Connecting distribution cable to backbone backbone Connecting to electronic source Connecting to electronic source and transmitter and transmitter Repairing a broken cable Repairing a broken cable

Transcript of Fiber Joints Fibers must be joined when Fibers must be joined when You need more length than you can...

Fiber JointsFiber Joints

Fibers must be joined whenFibers must be joined when• You need more length than you can get You need more length than you can get

on a single rollon a single roll• Connecting distribution cable to Connecting distribution cable to

backbonebackbone• Connecting to electronic source and Connecting to electronic source and

transmittertransmitter• Repairing a broken cableRepairing a broken cable

Splices v. Connectors Splices v. Connectors

A permanent join is a A permanent join is a splicesplice Connectors Connectors are used at patch are used at patch

panels, and can be disconnectedpanels, and can be disconnected

Optical LossOptical Loss

Intrinsic LossIntrinsic Loss• Problems the splicer Problems the splicer

cannot fixcannot fix Core diameter mismatchCore diameter mismatch Concentricity of fiber core or Concentricity of fiber core or

connector ferrulesconnector ferrules Core ellipticityCore ellipticity Numerical Aperture Numerical Aperture

mismatchmismatch• Images from LANshack and Images from LANshack and

tpub.com (links Ch 6a & 6c)tpub.com (links Ch 6a & 6c)

Optical LossOptical Loss

Extrinsic LossExtrinsic Loss• Problems the person doing Problems the person doing

the splicing can avoidthe splicing can avoid MisalignmentMisalignment Bad cleavesBad cleaves Air gapsAir gaps Contamination: Dirt, dust, Contamination: Dirt, dust,

oil, etc.oil, etc. ReflectanceReflectance

Measuring ReflectanceMeasuring Reflectance

The reflected light is a fraction of the The reflected light is a fraction of the incoming lightincoming light• If 10% of the light is reflected, that is a If 10% of the light is reflected, that is a

reflectance of 10 dBreflectance of 10 dB• If 1% of the light is reflected, 20 dBIf 1% of the light is reflected, 20 dB• Reflectance is not usually a problem for Reflectance is not usually a problem for

data networks, but causes ghosting in data networks, but causes ghosting in analog cable TV transmissionanalog cable TV transmission

• Angled connectors reduce reflectanceAngled connectors reduce reflectance

Acceptable LossesAcceptable Losses

Fiber & Fiber & JointJoint

Loss (max)Loss (max) Reflectance Reflectance (min)(min)

SM spliceSM splice 0.15 dB0.15 dB 50 dB50 dB

SM connectorSM connector 1 dB1 dB 30 dB30 dB

MM spliceMM splice 0.25 dB0.25 dB 50 dB50 dB

MM MM connectorconnector

0.75 dB0.75 dB 25 dB25 dB

ConnectorsConnectors

There are four typesThere are four types• Rigid Ferrule (most Rigid Ferrule (most

common)common)• Resilient ferruleResilient ferrule• Grooved plate hybridsGrooved plate hybrids• Expanded beamExpanded beam

Top image shows ferrules Top image shows ferrules from swiss-jewel.com (link from swiss-jewel.com (link Ch 6e)Ch 6e)

Lower image shows LC, SC, Lower image shows LC, SC, Biconic, and the obsolete Biconic, and the obsolete Deutsch 1000Deutsch 1000

• From thefoa.org (link Ch 6d)From thefoa.org (link Ch 6d)

Rigid Ferrule ConnectorsRigid Ferrule Connectors

2.5 mm ferrule2.5 mm ferrule STST

SCSC

FCFC Images from thefoa.org (link Ch 6d)Images from thefoa.org (link Ch 6d)

Rigid Ferrule ConnectorsRigid Ferrule Connectors 1.25 mm ferrule1.25 mm ferrule Small Form FactorSmall Form Factor

LCLC

MUMU

LX-5LX-5

Images from thefoa.org (link Ch 6d)Images from thefoa.org (link Ch 6d)

Obsolete ConnectorsObsolete Connectors

Simplex (1-fiber)Simplex (1-fiber) SMASMA

D4D4

BiconicBiconic

Images from thefoa.org (link Ch 6d)Images from thefoa.org (link Ch 6d)

Duplex ConnectorsDuplex Connectors

Old, bulkyOld, bulky FDDIFDDI

ESCONESCON

Images from thefoa.org (link Ch 6d)Images from thefoa.org (link Ch 6d)

Duplex ConnectorsDuplex Connectors

Newer, smallerNewer, smaller Small Form FactorSmall Form Factor

MT-RJMT-RJ

Opti-JackOpti-Jack

VolitionVolition

Images from thefoa.org (link Ch 6d)Images from thefoa.org (link Ch 6d)

Duplex ConnectorsDuplex Connectors New, popularNew, popular Small Form FactorSmall Form Factor

Duplex LCDuplex LC

Images from globalsources.com (link Ch 6f)Images from globalsources.com (link Ch 6f)

Ferrule PolishFerrule Polish

To avoid an air gapTo avoid an air gap Ferrule is polished flat, or Ferrule is polished flat, or Rounded (PC—Physical Rounded (PC—Physical

Contact), orContact), or Angled (APC)Angled (APC)

• Reduces reflectanceReduces reflectance• Cannot be mated with the Cannot be mated with the

other polish typesother polish types Image from LANshack (link Ch 6a)Image from LANshack (link Ch 6a)

FOCISFOCIS

Fiber Optic Connector Fiber Optic Connector Intermateability StandardIntermateability Standard• A document produced by a connector A document produced by a connector

manufacturer so others can mate to manufacturer so others can mate to their connectortheir connector

• Connectors with the same ferrule size Connectors with the same ferrule size can be mated with adaptorscan be mated with adaptors

• But 2.5 mm ferrules can not be mated But 2.5 mm ferrules can not be mated with 1.25 mm ferruleswith 1.25 mm ferrules

TelecommunicationsTelecommunications In telecommunications, SCIn telecommunications, SC

• and FCand FC

• are being replaced byare being replaced by

• LCLC in the USAin the USA

• MUMU in other countriesin other countries

DataData

In data In data communications, SC communications, SC and STand ST• are being replaced byare being replaced by

• LCLC

Connectorizing a CableConnectorizing a Cable

Epoxy-polish process (Proj. 4)Epoxy-polish process (Proj. 4)• Strip cable, strip and clean fiberStrip cable, strip and clean fiber• Inject adhesive, put primer on fiber, Inject adhesive, put primer on fiber,

insert fiberinsert fiber• Crimp connector, cleave protruding fiberCrimp connector, cleave protruding fiber• Air polish, final polishAir polish, final polish• Clean and inspect by microscopeClean and inspect by microscope• Test connector loss with power meterTest connector loss with power meter

Cable Type and ConnectorsCable Type and Connectors

Epoxy-polish process requires a cable Epoxy-polish process requires a cable jacket and strength member to make the jacket and strength member to make the connector durableconnector durable• It works for simplex, zip, or breakout cablesIt works for simplex, zip, or breakout cables• But loose-tube cables and ribbon cables But loose-tube cables and ribbon cables

contain bare fiber, and cannot be contain bare fiber, and cannot be connectorized this wayconnectorized this way

• Distribution cables contain 900 micron Distribution cables contain 900 micron buffered fiber – can be connectorized, but the buffered fiber – can be connectorized, but the connectors are not very strong and must be connectors are not very strong and must be protected by hardware such as a junction boxprotected by hardware such as a junction box

Breakout KitBreakout Kit

Provides Provides tubing that tubing that protects the protects the bare fiber so it bare fiber so it can be can be terminatedterminated• Picture from Picture from

fonetworks.com fonetworks.com (link Ch 4d)(link Ch 4d)

Mounting Methods for ConnectorsMounting Methods for Connectors AdhesivesAdhesives

• Epoxy (room temperature-cure or oven-Epoxy (room temperature-cure or oven-cure)cure)

• Quick-curing anaerobic adhesives (we Quick-curing anaerobic adhesives (we used this method in Proj 4)used this method in Proj 4)

• Hot-Melt adhesiveHot-Melt adhesive Crimping to hold the fiberCrimping to hold the fiber

• Like the Unicam – see link Ch 6hLike the Unicam – see link Ch 6h Splicing to preconnectorized pigtailsSplicing to preconnectorized pigtails

• Image of pigtail from fiberdyne.com (link Ch 6g)Image of pigtail from fiberdyne.com (link Ch 6g)

Mounting Methods ComparisonMounting Methods Comparison Epoxy-PolishEpoxy-Polish

• Takes longer, but costs less and has lowest Takes longer, but costs less and has lowest loss and reflectanceloss and reflectance

Anaerobic adhesiveAnaerobic adhesive• Faster than epoxy-polish but higher loss Faster than epoxy-polish but higher loss

because polishing is difficultbecause polishing is difficult CrimpingCrimping

• Easier, but more expensive and more lossEasier, but more expensive and more loss Splicing to preconnectorized pigtailSplicing to preconnectorized pigtail

• Very easy, but expensive and higher lossVery easy, but expensive and higher loss

Strip, Clean and CleaveStrip, Clean and Cleave

StripStrip – remove 900 micron buffer (if – remove 900 micron buffer (if present) and 250 micron coatingpresent) and 250 micron coating

CleanClean with alcohol and lint-free wipe with alcohol and lint-free wipe Cleave Cleave – scribe and snap; goal is a 90 – scribe and snap; goal is a 90

degree flat breakdegree flat break

End-Face PolishEnd-Face Polish

Polish on a flat glass plate for a Polish on a flat glass plate for a flat flat finishfinish

Polish on a rubber mat for a domed Polish on a rubber mat for a domed PC finishPC finish (Physical Contact) (Physical Contact)

Angled PC finish Angled PC finish is tilted at 8 is tilted at 8 degrees to avoid reflectance (difficult degrees to avoid reflectance (difficult to field-terminate)to field-terminate)

Cleaning ConnectorsCleaning Connectors

Keep dust caps onKeep dust caps on Use lint-free wipes and reagent-Use lint-free wipes and reagent-

grade isopropyl alcohol to avoid grade isopropyl alcohol to avoid attacking epoxyattacking epoxy

““Canned air” has propellant, so does Canned air” has propellant, so does compressed air from a hosecompressed air from a hose

SplicesSplices

Splices are a permanent join of two Splices are a permanent join of two fibersfibers• Lower attenuation and reflectance than Lower attenuation and reflectance than

connectorsconnectors• Stronger and cheaper than connectorsStronger and cheaper than connectors• Easier to perform than connectorizationEasier to perform than connectorization• Mass splicing does 12 fibers at a time, Mass splicing does 12 fibers at a time,

for ribbon cablesfor ribbon cables

Mass Fusion SplicingMass Fusion Splicing

Video from Video from fitel.fiberopticfitel.fiberoptic.com (link Ch .com (link Ch 6i)6i)

Fusion SplicingFusion Splicing

Melts the fibers together to form a Melts the fibers together to form a continuous fibercontinuous fiber

Expensive machineExpensive machine Strongest and best join for Strongest and best join for

singlemode fibersinglemode fiber• May lower bandwidth of multimode fiberMay lower bandwidth of multimode fiber

Corning videos 1-7 & 12Corning videos 1-7 & 12

Mechanical SplicingMechanical Splicing

Mechanically aligns fibersMechanically aligns fibers Contains index-matching gel to Contains index-matching gel to

transmit lighttransmit light Equipment cost is lowEquipment cost is low Per-splice cost is highPer-splice cost is high Quality of splice varies, but better Quality of splice varies, but better

than connectorsthan connectors Fiber alignment can be tuned using a Fiber alignment can be tuned using a

Visual Fault LocatorVisual Fault Locator