fiber and local are network understanding

Scalable. Robust. Cost-effective. Ready forwhat’s now and what’s next. If this is whatyou require from your local area network,then doesn’t it make sense to demand itfrom the technologies supporting it? That’swhy optical fiber is the ideal technology forlocal area networks.

The Benefits of Fiber OpticsIn its simplest terms, fiber optics is the technology of using “waveguides” to transport informationfrom one point to another in the form of light. Unlike the copper form of transmission, fiberoptics is not electrical in nature. A basic fiber optic system consists of a transmitting device, whichgenerates the light signal; an optical fiber cable, which carries the light; and a receiver, whichaccepts the light signal transmitted. The fiber itself is passive and does not contain any active,generative properties. (This basic information transmission sequence will be discussed in moredetail later.)

Optical fiber systems have many advantages over metallic-based communication systems. Theseadvantages include:

Large bandwidth, light weight and small diameterThe amount of information carried in two strands of optical fiber would require a copper cablefour inches in diameter. While today’s applications require an ever-increasing amount of band-width, it is important to consider the space constraints of many end-users. The relatively smalldiameter and light weight of optical cables make such installations in existing duct systems easyand practical, and saves valuable conduit space in these environments.

Understanding Fiber Optics and Local Area NetworksProducts, Services and Support

Corning Cable Systems

Contained InThis Guide

• The Benefits of Fiber Optics

• Optical Fiber Deconstructed

• Inside an Optical Fiber

• Optical Fiber Parameters

• The Basics of Fiber Optic Transmission

• Fiber Optic CablingBasics

• Fiber Optic Connectivity

1Corning Cable Systems

LANscape® Solutions Fiber Optic Cables ❘Photo LAN665

Easy installation and upgradesOptical fiber cables can be installed with the same equipment that is used toinstall copper and coaxial cables, with some modifications due to the small sizeand limited pull tension and bend radius of optical cables. System designerstypically plan optical systems that will meet growth needs for a 15- to 20-yearspan. Although sometimes difficult to predict, growth can be accommodated byinstalling spare fibers for future requirements. Installation of spare fibers todayis more economical than installing additional cables later.

Designed for future applications needsFiber optics is affordable today, as the price of electronics fall and optical cablepricing remains low. In many cases, fiber solutions are less costly than copper.As bandwidth demands increase rapidly with technological advances, fiber willcontinue to play a vital role in the long-term success of telecommunications.

Long distance signal transmissionThe low signal loss and superior signal integrity found in optical systems allowmuch longer intervals of signal transmission without active or passive process-ing than metallic-based systems.

SecurityUnlike metallic-based systems, the dielectric (non-conducting) nature of opticalfiber makes it impossible to remotely detect the signal being transmitted withinthe cable. The only way to do so is by actually accessing the optical fiber itself.Accessing the fiber requires intervention that is easily detectable by securitysurveillance. These circumstances make fiber extremely attractive for securityapplications.

Non-conductivityOptical fibers, because they are dielectric, can be installed in areas with electro-magnetic interference (EMI), including radio frequency interference (RFI).Areas with high EMI include utility lines, power-carrying lines and railroadtracks. All-dielectric cables are also ideal for areas of high-lightning-strike inci-dence.

Optical Fiber DeconstructedOptical fiber for telecommunications consists of three components:

• Core• Cladding• Coating

The core is the central region of an optical fiber through which light is trans-mitted. In general, telecommunications uses sizes from 8.3 micrometers (µm) to62.5 µm. The standard telecommunications core sizes in use today are 8.3 µm(single-mode), 50 µm (multimode) and 62.5 µm (multimode). (Single-mode andmultimode will be discussed shortly.) The diameter of the cladding surroundingeach of these cores is 125 µm. Core sizes of 85 µm and 100 µm have been usedin early applications, but are not typically used today.

Common Myths aboutOptical Fiber

MYTH: Optical fiber is fragile. FACT: Fiber may be made of glass, butdon’t let that fool you. Inch for inch, it’sstronger than steel. Optical fiber also ismore environmentally robust than copper,and does not corrode, rust or decay whenexposed to the environment.

MYTH: Optical fiber is so complex toinstall, it requires a specialist. FACT: Not at all. Unlike copper products,whose designs have become increasinglycomplex over the years to keep up withbandwidth demand, fiber technologies aretrending toward ever-easier designs whilestaying ahead of bandwidth demand.

MYTH: Optical fiber is cost-prohibitive. FACT: Actually, optical fiber is usually theless costly investment for your networkbecause of its nearly limitless bandwidthcapacity and ease of upgrade.

MYTH: Testing and troubleshooting isdifficult. FACT: Optical testing is no more difficultthan coaxial copper cable testing and isoften simpler, as fewer parameters areneeded to ensure the operability of opticalfiber. For example, while copper technolo-gies are affected by electromagnetic inter-ference and “cross talk,” and therefore mustbe tested for this, fiber suffers no suchissue.

Understanding Fiber Optics and Local Area Networks

2 Corning Cable Systems

Core8 µm to 62.5 µm

Cladding125 µm

Coating250 µm

Figure 1 - Cross-Section of Typical Fiber



To put these sizes into perspective, compare them to a humanhair, which is approximately 70 µm or 0.003 inch. The coreand cladding are manufactured together as a single piece of sil-ica glass with slightly different compositions and cannot beseparated from one another. Contrary to myth, this glass doesnot have a hole in the core, but is completely solid throughout.

The third section of an optical fiber is the outer protectivecoating which has a diameter of 250 µm. This coating is typi-cally an ultraviolet (UV) light-cured acrylate applied during themanufacturing process to provide physical and environmentalprotection for the fiber. During the installation process, thiscoating is stripped away from the cladding to allow proper ter-mination to an optical transmission system.

Types of fiberOnce light enters an optical fiber, it travels in a stable statecalled a mode. There can be from one to hundreds of modesdepending on the type of fiber. Each mode carries a portion ofthe light from the input signal. Generally speaking, the num-ber of modes in a fiber is a function of the relationshipbetween core diameter, numerical aperture and wavelength,which will be discussed later.

Every optical fiber falls into one of two categories: • Single-mode • Multimode

It is impossible to distinguish between single-mode and multi-mode fiber with the naked eye. There is no difference in out-ward appearances. Only the core size is different. Both fibertypes act as a transmission medium for light, but they operatein different ways, have different characteristics and serve differ-ent applications.

Single-mode fiber allows for only one pathway, or mode, oflight to travel within the fiber. The core size is 8.3 µm. Single-mode fibers are used in applications where low-signal-loss andhigh-data-rates are required, such as on long spans whererepeater/amplifier spacing needs to be maximized.

Multimode fiber allows more than one mode of light.Common multimode core sizes are 50 µm and 62.5 µm. Of thetwo, 50 µm fiber, particularly 50 µm fiber optimized for lasertransmission, offers the highest bandwidth. Multimode fiber isbetter suited for shorter distance applications. Where costlyelectronics are heavily concentrated, the primary cost of thesystem does not lie with the cable. In such a case, multimodefiber is more economical because it can be used with low-costtransmitters for high bandwidth.

Inside an Optical Fiber

Index of refraction (IOR)The index of refraction (IOR) is a way of measuring the speedof light in a material. The index of refraction is calculated bydividing the speed of light in a vacuum (the fastest possiblespeed of light) by the speed of light in some other medium.The larger the index of refraction, the more slowly that lighttravels in that medium.

Total internal reflectionWhen a light ray traveling in one material hits a differentmaterial and reflects back into the original material withoutany loss of light, total internal reflection occurs. Since the coreand cladding are constructed from different compositions ofglass, theoretically, light entering the core is confined to theboundaries of the core because it reflects back whenever it hitsthe cladding. For total internal reflection to occur, the index ofrefraction of the core must be higher than that of the cladding.

Numerical aperture and the “acceptance cone”Electrical signals are converted to light signals before theyenter an optical fiber. To ensure that the signals reflect andtravel correctly through the core, the light must enter the corethrough an imaginary acceptance cone. The size of this accept-ance cone is a function of the refractive index differencebetween the core and the cladding.

Coating Coating

Core Core

Cladding Cladding

Multimode Fiber Single-Mode Fiber

Figure 2 - Fiber Categories CoreCladding

Light Ray

Figure 3 - Total Internal Reflection



In simpler terms, there is a maximum angle from the fiber axisat which light may enter the fiber so that it will propagate, ortravel, in the core of the fiber. The sine of this maximum angleis the numerical aperture (NA) of the fiber. Fiber with a largerNA requires less precision to splice and work with than fiberwith a smaller NA. Single-mode fiber has a smaller NA thanmultimode fiber.

Optical Fiber ParametersAs with any type of transmission system, certain parametersaffect the system’s operation.

WavelengthLight that can be seen by the unaided human eye is said to bein the visible spectrum. In the visible spectrum, wavelength canbe described as the color of light.

To put this into perspective, take a look at Figure 5. Noticethat the colors of the rainbow – red, orange, yellow, green,blue, (indigo, not shown) and violet – fall within the visiblespectrum. Optical fiber transmission uses longer wavelengthswhich are invisible to the unaided eye. (Longer wavelengthshave higher readings; for example, red light has a longer wave-length than blue light.) Typical optical transmission wave-lengths are 850 nanometers (nm), 1300 nm and 1550 nm.

Safety note: Never look into the end of a fiber that may have a lasercoupled to it. Laser light is invisible and can damage the eyes.Viewing it directly does not cause pain. The iris of the eye will notclose involuntarily as when viewing a bright light; consequently, seri-ous damage to the retina of the eye is possible. Should accidental expo-sure to laser light be suspected, an eye examination should bearranged immediately.

Both lasers and light emitting diodes (LEDs) are used to trans-mit light through optical fiber. (More information on lasersand LEDs is available later in the text.) Lasers typically trans-mit at 850, 1310 and 1550 nm, making them ideal for laser-optimized multimode fibers (850 nm) and single-mode fiber(1310 and 1550 nm). LEDs are used at 850 or 1300 nm, making them useful for standard multimode fiber.

WindowThere are operational ranges of wavelengths at which the fiberbest operates. Each range is known as an operating window.Each window is centered on the typical operational wave-length.

Window Operating Wavelength800-900 nm 850 nm1250-1350 nm 1310 nm1500-1600 nm 1550 nm

These wavelengths were chosen because they best match thetransmission properties of available light sources with thetransmission qualities of optical fiber.

FrequencyThe frequency of a system is the speed of modulation of thedigital or analog output of the light source; in other words, thenumber of pulses per second emitted from the light source (seeFigure 6). Frequency is measured in units of hertz (Hz), where1 hertz is equal to 1 pulse or cycle per second.

A more practical measurement for optical communications ismegahertz (MHz) or millions of pulses per second.

Light ray A: entered acceptance cone; transmitted throughthe core by total internal reflection (TIR)Light ray B: did not enter acceptance cone; signal lost

Figure 4 - Acceptance Cone

Increasing Frequency

Figure 5 - Visible Spectrum of Light

Longer Wavelength

Fibe

rOpt

icAp

plic

atio

ns



Intrinsic attenuationAttenuation is the loss of optical power as light travels down afiber. It is measured in decibels (dB). Over a set distance, afiber with a lower attenuation will allow more power to reachits receiver than a fiber with higher attenuation.

Attenuation can be caused by several factors, but is generallyplaced in one of two categories: intrinsic or extrinsic.

Intrinsic attenuation occurs due to something inside or inher-ent to the fiber. It is caused by impurities in the glass duringthe manufacturing process. As precise as manufacturing is,there is no way to eliminate all impurities, though technologi-cal advances have caused attenuation to decrease dramaticallysince 1970. When a light signal hits an impurity in the fiber,one of two things will occur: it will scatter or it will beabsorbed.

ScatteringRayleigh scattering accounts for the majority (about 96 per-cent) of attenuation in optical fiber. Light travels in the coreand interacts with the atoms in the glass. The light waves elas-tically collide with the atoms, and light is scattered as a result.

Some scattered light is reflected back toward the light source(input end). This is a property that is used in an optical timedomain reflectometer (OTDR) to test fibers. This same princi-ple applies to analyzing loss associated with localized events inthe fiber, such as splices.

AbsorptionThe second type of intrinsic attenuation in fiber is absorption.Absorption accounts for 3-5 percent of fiber attenuation. Thisphenomenon causes a light signal to be absorbed by naturalimpurities in the glass. Unlike scattering, absorption can belimited by controlling the amount of impurities during themanufacturing process.

Extrinsic attenuationThe second category of attenuation is extrinsic attenuation.Extrinsic attenuation can be caused by two external mecha-nisms: macrobending or microbending. Both cause a reductionof optical power.

MacrobendingIf a bend is imposed on an optical fiber, strain is placed on thefiber along the region that is bent. The bending strain willaffect the refractive index and the critical angle of the light rayin that specific area. As a result,light traveling in the core canrefract out, and loss occurs.

A macrobend is a large-scalebend that is visible; for exam-ple, a fiber wrapped around aperson’s finger. This loss is gen-erally reversible once bends arecorrected.

To prevent macrobends, alloptical fiber (and optical fiber cable) has a minimum bendradius specification that should not be exceeded. This is arestriction on how much bend a fiber can withstand beforeexperiencing problems in optical performance or mechanicalreliability.

MicrobendingThe second extrinsic cause of attenuation is a microbend. Thisis a small-scale distortion, generally indicative of pressure onthe fiber. Microbending may be related to temperature, tensilestress, or crushing force. Like macrobending, microbendingwill cause a reduction of optical power in the glass.

1 second

1 second

B

A 4 pulses/second(4 Hz)

7 pulses/second(7 Hz)

"B" represents a higher frequency than "A"

Figure 6 - Frequency MeasurementMacrobending Rule of Thumb

The rule of thumb for minimumbend radius is:• 1.5-inch for bare, single-mode

fiber• 10 times the cable’s outside

diameter (O.D.) for non-armored cable

• 15 times the cable’s O.D. for armored cable

Figure 7 - Minimum Bend Radius



Microbending is very localized, and the bend may not be clear-ly visible upon inspection. With bare fiber, microbending maybe reversible; in the cabling process, it may not. Microbendingattenuation affects all optical wavelengths.

DispersionDispersion is the “spreading” of a light pulse as it travels downa fiber. As the pulses spread, or broaden, they tend to overlapand are no longer distinguishable by the receiver as 0s and 1s.Light pulses launched close together (high data rates) thatspread too much (high dispersion) result in errors and loss ofinformation.

Chromatic dispersion occurs as a result of the range of wave-lengths in the light source. Light from lasers and LEDs con-sists of a range of wavelengths. Each of these wavelengths trav-els at a slightly different speed. Over distance, the varyingwavelength speeds cause the light pulse to spread in time. Thisis of most importance in single-mode applications.

The index of refraction of a material is dependent on the wave-length, so each frequency component actually travels at aslightly different speed. As the distance increases, the pulsebecomes broader as a result. Material dispersion is a signifi-cant source of dispersion in single-mode fiber only.

Modal dispersion affects multimode fibers only and is a resultof the modes of light traveling down the fiber arriving at thereceiver at different times, causing a spreading effect. Gradedindex profiles, only used in multimode fibers, are used to miti-gate the effects of modal dispersion.

BandwidthIn simplest terms, bandwidth is the amount of information afiber can carry so that every pulse is distinguished by thereceiver at the end.

As discussed in the previous section, dispersion causes lightpulses to spread. The spreading of these light pulses causesthem to merge together. At a certain distance and frequency,the pulses become unreadable by the receiver. The multiplepathways of a multimode fiber cause this overlap to be muchgreater than for single-mode fiber. These different paths havedifferent lengths, which cause each mode of light to arrive at adifferent time.

System bandwidth is measured in megahertz (MHz) at one km.In general, when a system’s bandwidth is 20 MHz•km, itmeans that 20 million pulses of light per second will traveldown 1 km (1000 m) of fiber, and each pulse will be distin-guishable by the receiver.

The Basics of Fiber Optic Transmission

As depicted in Figure 10, information (voice, data, or video) isencoded into electrical signals. At the light source, these elec-trical signals are converted into light signals. It is important tonote that fiber has the capability to carry either analog or digi-tal signals. Many people believe that fiber can transmit onlydigital signals due to the on/off binary characteristic of thelight source. The intensity of the light and the frequency atwhich the intensity changes can be used for AM and FM ana-log transmission.

Once the signals are converted to light, they travel down thefiber until they reach a detector, which changes the light sig-nals back into electrical signals. (This is called OEO, or opti-cal-to-electrical-to-optical conversion.) The area from lightsource to detector constitutes the passive transmission subsys-tem; i.e. that part of the system manufactured and sold byCorning Cable Systems. Finally, the electrical signals aredecoded into information in the form of voice, data or video.

Inside of each of the electronics (switches, routers, etc) residesa receiver/photodetector to accept the incoming informationand a transmitter to send the information back out on the net-work. Typical switches in a local area network use an OEO

Figure 8 - Microbending

Input Pulse

Output Pulse

Optical FiberT2 > T1

T1 T2

Pulse width is measured at full width-half maximum; in otherwords, the full width of the pulse, at half the maximum pulseheight. Dispersion limits how fast, or how much, information canbe sent over an optical fiber.

Figure 9 - Dispersion



conversion. The data comes into the switch as an optical signal, isconverted into an electrical signal and switched/routed as needed.The signal is then converted back to an optical signal and sentout the port. OEO is not protocol transparent like a true opticalswitch, but does allow for the 3Rs (re-amplification, re-shape andre-time) of digital signals.

Lasers and LEDsHistorically, light emitting diode (LED) devices have been usedwith multimode fiber, and are inexpensive compared to single-mode fiber lasers. The light from the LED is not very intense,but is sufficient to couple enough power to achieve the distancesneeded at lower data rates. LED transmitters have been deployedfor use at 850 nm and 1300 nm, up to speeds of 622 Mb/sec.However, because LEDs cannot modulate faster than 622Mb/sec, a new technology was developed for gigabit speeds andabove.

Vertical cavity surface emitting lasers (VCSELs) are low-costlasers that operate at 850 nm on multimode fiber to support giga-bit speeds. As a result of their higher speed capabilities,VCSELsare the optical sources utilized in transmitters for 1 gigabit and 10gigabit Ethernet multimode systems. The light emitted is morepowerful and more concentrated than the light from LEDs andprovides much higher system performance. VCSELs are also sig-nificantly less expensive than typical single-mode fiber lasers anduse far less power, requiring far less cooling.

Fabry-Perot lasers can operate in the 850, 1310 and 1550 nmwindows and are typically used for single-mode applications.

They offer a higher power output than VCSELs but are alsomore expensive (though less expensive than distributed feedbacklasers, which are also used in single-mode systems).

Fiber Optic Cabling Basics

Cable environmentsIn general, fiber optic cable can be categorized by its deploy-ment environment.

Outdoor: Outside plant (OSP) cables must withstand a varietyof environmental and mechanical extremes. The cable mustoffer excellent attenuation performance over a wide range oftemperatures, resist water ingress, sustain years of ultravioletradiation from direct sunlight and tolerate a wide range ofmechanical forces.

Indoor: Inside plant cables generally experience a more con-trolled, stable environment. Therefore, performance require-ments are based on other factors. The cables must meet therequirements of the National Electrical Code® (NEC®) andlocal building codes based upon their installed location. Thesecables should also be easy to terminate.

Indoor and outdoor: Corning Cable Systems led the develop-ment of flame-retardant indoor/outdoor cables. These cablesuse specialty materials to meet the flame-retardant require-ments of the indoor environment. They also provide reliablewaterblocking and robust construction critical for OSP use.

Figure 10 - Information Transmission Sequence

ZA-2630

UV-Resistant, Flame-RetardantOuter JacketColor-Coded 900 µm TBII® Buffered Fibers Water-Swellable Strength Members

UV-Resistant, Flame-RetardantOuter JacketColor-Coded 900 µm TBII Buffered Fibers Water-Swellable Strength Members

Central Strength Member


FREEDM® One MIC® CableIndoor/Outdoor

6-fiber

12-fiber

24-fiber



Figure 12 - FREEDM One 6-, 12- and 24-Fiber Cable ❘Drawing ZA-2630

ZA-2630






6-fiber

12-fiber

24-fiber



ZA-2630






6-fiber

12-fiber

24-fiber





Cable ratingsArticle 770 of the National Electrical Code® (NEC®) requiresindoor fiber cables to meet different requirements based onwhere they are placed in the environment requirement: Listedmost to least stringent, they are plenum, riser and general pur-pose areas. • Plenum area: A compartment or chamber that forms part

of the air distribution system and to which one or more air ducts are connected. Any space with a primary function of air handling is also considered a plenum space. These cables must be listed OFNP or OFCP in accordance with the NEC.

• Riser: An opening or shaft through which cable may pass vertically from floor to floor in a building. These cables must be listed OFNR or OFCR in accordance with the NEC.

• General purpose: All other indoor areas that are not plenumor risers. These cables must be listed OFN or OFC in accordance with the NEC.

Typical cable typesLoose tube cables: Loose tube cables like Corning CableSystems ALTOS® Cables are designed primarily for OSP environments and campus backbone applications. One to 12fibers are placed in individual, waterblocked buffer tubes toisolate them from external forces and are typically strandedaround a fiberglass central strength member to provide addi-tional strength and resistance. A loose tube cable typically will hold up to 288 fibers in total within these tubes. With more than 25 years of successful operation in the field,the loose tube cable design has been used more extensivelythan any other in the industry. It provides stable and highlyreliable optical transmission characteristics over a wide temper-ature range. Corning Cable Systems offers stranded loose tubecables for outdoor as well as indoor and indoor/outdoor riserapplications.

PE Outer Jacket

Filled Buffer Tube

Dielectric Strength Members(as required)

Dielectric Central Member

Water-Swellable Tape

Ripcord

Fibers

Water-Swellable Yarn

Figure 11 - Loose Tube Cable ❘ Drawing CPC-220/1/3

Tight-buffered cables: Tight-buffered cables are designed foruse in building and data center backbones, horizontal applica-tions and patch cords and equipment cables. This provendesign is the most widely deployed cable type for indoor appli-cations. Tight-buffered cables contain 250 µm optical fibersthat are directly coated with a thermoplastic buffer to a diame-ter of 900 µm. Tight-buffered cables are desirable for intra-building applications because of their ability to meet buildingfire code requirements as well as their increased physical flexi-bility, smaller bend radius and easier handling characteristics.These cables, however, are more sensitive to temperatureextremes and mechanical disturbances than loose tube or rib-bon cables and, with the exception of Corning Cable SystemsFREEDM® Fan-Out and FREEDM One Cables, do not havewaterblocking materials.

Corning Cable Systems FREEDM Fan-Out Cables utilizeflame-retardant, 900 µm TBII® Buffered Fiber subunits sur-rounded by water-resistant, dielectric strength members andprotected by a flexible, flame-retardant outer jacket. TheseOFNR and FT-4 rated cables eliminate the need for a transi-tion splice entering the building and have 2.9 mm subunits toenable easy field termination. These environmentally robust,small diameter cables are ideal for routing inside/outside build-

ings into riser spaces to security, surveillance or monitoringcameras, and within telecommunications rooms and worksta-tions.

FREEDM® One Cable offers select attributes of both indoorand OSP cables. Selecting a FREEDM One Cable is oftenmore cost effective than making a splice transition from OSPto indoor cabling. FREEDM One Cable is available with riserand plenum ratings.

Corning Cable Systems MIC® Cables, available in 2-144 fibers,are constructed by stranding the desired number of color-coded tight-buffered optical fibers around a dielectric centralmember, applying a layer of strength member yarns andextruding a flame-retardant jacket over the cable core. CorningCable Systems’ unique TBII® Buffered Fiber buffering methodallows for easy, one-pass stripping and a slick jacket on 2-24fiber tight-buffered cables for easier pulling during cableinstallation.

Ribbon Cables: Ribbon cables like Corning Cable SystemsLANscape® Solutions Ribbon Riser and Plenum Cables aredesigned primarily for indoor use, though outside andinside/outside versions are also available. The cable ribboniz-ing process takes 12 individual fibers, positions them into a

horizontal array, and extrudes an acrylate coating onto andaround them. These 12-fiber ribbons can then be stacked via acable buffering process inside a central tube. Dielectricstrength members are typically stranded around the tube foradditional durability.

Ribbon cables offer high fiber density in a small diameter pack-age – a 96-fiber ribbon cable may only be half an inch in diam-eter. They are also ideal for mass fusion splicing or for quicktermination with MTP® 12-fiber connectors. (See more onconnectors in the next section of this guide.)

Fiber Optic Connectivity

One of the most important steps in the installation of fiberoptic systems is the termination of the individual fibers. Thereare several widely used termination methods. Field installingthe connector is commonly done using either an epoxy/polishconnector or the labor-saving no-epoxy, no polish connector.Fusion splicing of pig-tails is a common practice in single-mode applications. Finally, a fast growing approach to termina-tion is to purchase factory terminated assemblies in the form ofcomplete pre-terminated solutions.

Field installable connectorsNo epoxy, no polish (NENP) connectors have become a widelydeployed connector termination technology. As its name sug-gests, this connector type eliminates the most laborious tasksassociated with traditional connectors: the epoxy and polish ofthe fibers. These connectors utilize mechanical splicing, anoptical junction where two or more fibers are aligned and heldin place by a self-contained assembly. In an NENP connector,the fiber to be terminated is inserted into the connector bodyand mechanically spliced to an existing pre-polished, factory-installed fiber stub.

Corning Cable Systems’ UniCam® Connectors, which areNENP connectors, consistently exhibit excellent end-facegeometry characteristics, as the polishing and epoxy insertionand adhesion are precisely measured and controlled in the fac-



Outer Jacket

Dielectric Strength Members

Ripcord

TBII® Buffered Fiber

Figure 14 - 6-Fiber OFNP MIC Cable ❘ Drawing CPC-220/1/37

Flame-RetardantOuter Jacket

RipcordsDielectric Strength

MembersBuffer Tube

Optical Fiber Ribbons

Ribbon Riser Cable

ZA-2566


Ripcords

Dielectric StrengthMembers

Buffer Tube



Ripcords


Buffer Tube




MembersBuffer Tube

Ribbon Riser Cable

Z


Ripcords


Buffer Tube



Ripcords


Buffer Tube


Figure 13 - Ribbon Riser Cable ❘ Drawing ZA-2566



MembersBuffer Tube


Ribbon Riser Cable

ZA-2566


Ripcords


Buffer Tube



Ripcords


Buffer Tube



tory. Unlike a traditional epoxy and polish connector, aUniCam® Connector’s insertion loss and reflectance values aremuch more consistent and reliable.

Reflectance, in particular, is not controlled or typically meas-ured during field termination. The elimination of theseprocesses in the field dramatically increases yield, performanceconsistency and drastically increases ease of installation. In fact,they require only a fiber-optic stripper, a cleave tool, the work-station installation tool and an alcohol pad. As a result, assem-bly space can be kept to a minimum, setup is quick and assem-bly is relatively fast and easy with no consumables. When tak-ing into account the material, labor and consumables costs of

termination, the UniCam Connector is the most cost-effective.However, epoxy and polish connectors are also widelydeployed as field-installable connectors. There are severaltypes of connectors within this broad category, the primary dif-ference being the type of epoxy utilized to adhere the fiberwithin the ferrule of the connector (i.e., heat cure, UV cureand anaerobic). The process for terminating an epoxy and pol-ish connector includes preparing the connector and consum-ables, injecting epoxy into the ferrule of the connector, feedingthe fiber through the ferrule micro-hole, allowing the epoxy tocure, scribing the fiber stub protruding from the ferrule, andthen following a series of polishing steps. Polishing in the fieldis most typically performed using a hand-polishing procedure.

Splicing pig tailsA common approach to providing high quality end-face termi-nations is to splice a pig tail. A fiber optic pig tail is a factory-finished connector with a pre-determined length of fiberattached. This length of fiber can be spliced, typically viafusion splice; however, it can be mechanically spliced to anoth-er segment of cable to complete the cable run. The factory- ormachine-finished connector enables the installer to provide aconnector type that may be difficult to achieve using a fieldinstallable connector, such as an APC connector. Pig tail splic-ing requires a splice tray and housing to ensure these connec-tions are well protected from physical or mechanical factors.

Fusion splicingFusion splicing consists of aligning and then fusing togethertwo stripped, cleaned and cleaved fibers with an electric arc.The fiber ends can be positioned and aligned using variousmethods, and can be manual or automatic. This is typicallyaccomplished with the aid of a viewing scope, video camera ora specialized type of optical power meter. High voltage appliedto the electrodes contained in the splicer generates an arcacross the fiber ends as the fibers are moved together, fusing

Figure 15 - Fusion Splicing Area on the X77 Fusion Splicer ❘Drawing ZA-703

125

900

125

900

Electrode ArcsFiber Routing GuideV-Groove

Stage Adjust onthe X, Y, Z Planes

to Align Fibers

Stripped, Cleaned andCleaved Fibers are Brought Together

During the ArcLID-SYSTEM

UnitReceiver

LID-SYSTEM®Unit

Transmitter

ZA-703


UniCam SC Multimode Connectors ❘ Photo LAN685

ST® Compatible Connector

ZA-2828

SC Connector

MT-RJ ConnectorLC Connector

MTP® Connector

PUSH

CONECPul l

TO REMOVE

MU Simplex Connector

FC Connector

The Most Commonly UsedConnector Types


the fibers. Corning Cable Systems offers several fusion splicermodels, including the Model X77 and X75 Micro FusionSplicers for fast, reliable fusion splicing at an economical price.

Preterminated solutionsA value-adding innovation for the security market is the use ofpreterminated solutions in the indoor and outside plant environ-ment. This solution eliminates field termination, and thereforeenables deployment at speeds several times faster than traditionalfield installation methods. The traditional installation of fiber ter-minals and closures, particularly in an outside plant environment,is a time-consuming and costly task. Minimizing these issues,coupled with the quality and reliability of a factory-terminated-and-tested system, maximizes the probability of rapid, cost effec-tive, flexible and high-performance installations.

Plug & Play™ Universal Systems is a preterminated cabling sys-tem for indoor applications. Preterminated cable trunks with afactory-installed protective pulling grip are routed throughthe cabling pathways and spaces. Once deployed, the pulling gripis removed and the exposed connectors on both ends of thetrunks are plugged into patch panels or system equipment.Because the trunks use high-density MTP® Connectors on theends, they plug quickly and easily into modules or harnesses forsimple, fast, modular solutions that are easily scalable.

Corning Cable Systems’ Plug & Play™ OSP Systems utilizes stan-dard optical fiber cables upon which network access points arepre-installed at customer-specified locations along the length ofthe cable. The cable and network access points are tested andshipped as a complete distribution cable/terminal system. Plug &Play OSP Systems can be deployed aerially or below ground inthe outside plant.

Optical hardware:Optical hardware is another key component in the complete opti-cal cable infrastructure, as it provides optical connection manage-ment, protection of optical connections, labeling of optical cir-cuits, consolidation points for multiple cable runs, and security ofoptical connections.

Optical hardware selection is typically based on environment,volume of connections and type of connections. There are manyhardware options to choose from when designing a security net-work. Typical options include splice closures, pedestals, cabinetsand housings; hardware that is rack- and wall-mountable, out-door weather-proof, industrial-grade, aerial, below-ground, directburied, high-fiber-count, low-fiber-count and secure/lockableproducts, just to name a few.

Plug & Play OSP System ❘ Photo LAN725

Plug & Play Universal Systems ❘ Photo LAN656


Corning Cable Systems LLC • PO Box 489 • Hickory, NC 28603-0489 USA 800-743-2675 • FAX: 828-901-5973 • International: +1-828-901-5000 • www.corning.com/cablesystemsCorning Cable Systems reserves the right to improve, enhance and modify the features and specifications of Corning Cable Systems productswithout prior notification. ALTOS, FREEDM, LANscape, MIC and UniCam are registered trademarks of Corning Cable Systems Brands, Inc. Plug &Play and Pretium are trademarks of Corning Cable Systems Brands, Inc. MTP is a registered trademark of USConec Ltd. Discovering BeyondImagination is a trademark of Corning Incorporated. ST is a registered trademark of Lucent Technologies. All other trademarks are the propertiesof their respective owners. Corning Cable Systems is ISO 9001 certified. © 2006 Corning Cable Systems. All rights reserved. Published in the USA.LAN-737-EN / May 2006 / 10M


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