A optical fiber cable with a clear jacket. These cables are used mainly for digital audio connections between devices.A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an, but containing one or more that are used to carry light. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed.
Different types of cable are used for different applications, for example, long distance, or providing a high-speed data connection between different parts of a building. A multi-fiber cableOptical fiber consists of a and a layer, selected for due to the difference in the between the two. In practical fibers, the cladding is usually coated with a layer of.
Fiber Optic Interconnects, Patch Cords & Pigtails F91BN1NNNSNM001 Home Products Fiber Optic Systems Fiber Optic Cable Assemblies Fiber Optic Interconnects, Patch Cords & Pigtails.
This coating protects the fiber from damage but does not contribute to its properties. Individual coated fibers (or fibers formed into ribbons or bundles) then have a tough layer or core tube(s) extruded around them to form the cable core. Several layers of protective sheathing, depending on the application, are added to form the cable. Rigid fiber assemblies sometimes put light-absorbing ('dark') glass between the fibers, to prevent light that leaks out of one fiber from entering another.
This reduces between the fibers, or reduces in fiber bundle imaging applications. An optical fiber breakout cableFor use in more strenuous environments, a much more robust cable construction is required. In loose-tube construction the fiber is laid into semi-rigid tubes, allowing the cable to stretch without stretching the fiber itself. This protects the fiber from tension during laying and due to temperature changes. Loose-tube fiber may be 'dry block' or gel-filled. Dry block offers less protection to the fibers than gel-filled, but costs considerably less. Instead of a loose tube, the fiber may be embedded in a heavy polymer jacket, commonly called 'tight buffer' construction.
Tight buffer cables are offered for a variety of applications, but the two most common are ' and '. Breakout cables normally contain a ripcord, two non-conductive dielectric strengthening members (normally a glass rod epoxy), an aramid yarn, and 3 mm buffer tubing with an additional layer of Kevlar surrounding each fiber.
The ripcord is a parallel cord of strong yarn that is situated under the jacket(s) of the cable for jacket removal. Distribution cables have an overall Kevlar wrapping, a ripcord, and a 900 micrometer buffer coating surrounding each fiber. These fiber units are commonly bundled with additional steel strength members, again with a helical twist to allow for stretching.A critical concern in outdoor cabling is to protect the fiber from contamination by water. This is accomplished by use of solid barriers such as copper tubes, and water-repellent jelly or water-absorbing powder surrounding the fiber.Finally, the cable may be armored to protect it from environmental hazards, such as construction work or gnawing animals. This section needs expansion. You can help. ( June 2008).
OFC: Optical fiber, conductive. OFN: Optical fiber, nonconductive. OFCG: Optical fiber, conductive, general use. OFNG: Optical fiber, nonconductive, general use. OFCP: Optical fiber, conductive, plenum. OFNP: Optical fiber, nonconductive, plenum.
OFCR: Optical fiber, conductive, riser. OFNR:. OPGW:. ADSS:. OSP: Fiber optic cable, outside plant.
MDU: Fiber optics cable, multiple dwelling unitJacket material The jacket material is application-specific. The material determines the mechanical robustness, chemical and UV radiation resistance, and so on. Some common jacket materials are, and.Fiber material There are two main types of material used for optical fibers: glass and plastic.
They offer widely different characteristics and find uses in very different applications. Generally, is used for very short-range and consumer applications, whereas glass fiber is used for short/medium-range and long-range telecommunications. Color coding Patch cords The buffer or jacket on patchcords is often color-coded to indicate the type of fiber used. The strain relief 'boot' that protects the fiber from bending at a connector is color-coded to indicate the type of connection.
Connectors with a plastic shell (such as ) typically use a color-coded shell. Blue. Orange. Green. Red. Grey. Yellow.
Brown. Violet.
Black. White.
Pink. TurquoiseEach element is in a tube within the cable (not a blown fibre tube) The cable elements start with the red tube and are counted around the cable to the green tube. Active elements are in white tubes and yellow fillers or dummies are laid in the cable to fill it out depending on how many fibres and units exists – can be up to 276 fibres or 23 elements for external cable and 144 fibres or 12 elements for internal.
The cable has a central strength member normally made from fiberglass or plastic. There is also a copper conductor in external cables.Propagation speed and delay Optical cables transfer data at the in glass. This is the speed of light in vacuum divided by the of the glass used, typically around 180,000 to 200,000 km/s, resulting in 5.0 to 5.5 microseconds of latency per km. Thus the round-trip delay time for 1000 km is around 11 milliseconds. This article may be too technical for most readers to understand. Please to, without removing the technical details. ( April 2012) Typical modern multimode graded-index fibers have 3 dB/km of attenuation loss (50% loss per km) at a wavelength of 850 nm, and 1 dB/km at 1300 nm.
Singlemode loses 0.35 dB/km at 1310 nm and 0.25 dB/km at 1550 nm. Very high quality singlemode fiber intended for long distance applications is specified at a loss of 0.19 dB/km at 1550 nm. POF loses much more: 1 dB/m at 650 nm. Plastic optical fiber is large core (about 1 mm) fiber suitable only for short, low speed networks such as within cars.Each connection made adds about 0.6 dB of average loss, and each joint (splice) adds about 0.1 dB.
Depending on the transmitter power and the sensitivity of the receiver, if the total loss is too large the link will not function reliably.Invisible infrared light is used in commercial glass fiber communications because it has lower attenuation in such materials than visible light. However, the glass fibers will transmit visible light somewhat, which is convenient for simple testing of the fibers without requiring expensive equipment. Splices can be inspected visually, and adjusted for minimal light leakage at the joint, which maximizes light transmission between the ends of the fibers being joined.The charts at 'Understanding wavelengths In fiber optics' and 'Optical power loss (attenuation) in fiber' illustrate the relationship of visible light to the infrared frequencies used, and show the absorption water bands between 850, 1300 and 1550 nm.Safety The infrared light used in telecommunications cannot be seen, so there is a potential hazard to technicians. The eye's natural defense against sudden exposure to bright light is the, which is not triggered by infrared sources.
In some cases the power levels are high enough to damage eyes, particularly when lenses or microscopes are used to inspect fibers that are emitting invisible infrared light. Inspection microscopes with optical safety filters are available to guard against this. More recently indirect viewing aids are used, which can comprise a camera mounted within a handheld device, which has an opening for the connectorized fiber and a USB output for connection to a display device such as a laptop. This makes the activity of looking for damage or dirt on the connector face much safer.Small glass fragments can also be a problem if they get under someone's skin, so care is needed to ensure that fragments produced when fiber are properly collected and disposed of appropriately.Hybrid cables There are hybrid optical and electrical cables that are used in wireless outdoor Fiber To The Antenna (FTTA) applications.
In these cables, the optical fibers carry information, and the electrical conductors are used to transmit power. These cables can be placed in several environments to serve antennas mounted on poles, towers, and other structures.According to Generic Requirements for Hybrid Optical and Electrical Cables for Use in Wireless Outdoor Fiber To The Antenna (FTTA) Applications, these hybrid cables have optical fibers, twisted pair/quad elements, coaxial cables or current-carrying electrical conductors under a common outer jacket.
The power conductors used in these hybrid cables are for directly powering an antenna or for powering tower-mounted electronics exclusively serving an antenna. They have a nominal voltage normally less than 60 VDC or 108/120 VAC. Other voltages may be present depending on the application and the relevant National Electrical Code (NEC).These types of hybrid cables may also be useful in other environments such as Distributed Antenna System (DAS) plants where they will serve antennas in indoor, outdoor, and roof-top locations. Posinna, Mariddetta (Apr 1, 2014).
From the original on 2016-04-20. Retrieved 2016-04-11.
National Instruments' Developer Zone. From the original on 2015-12-22. Retrieved 2015-10-08.Hecht, Jeff (2002).
Understanding Fiber Optics (4th ed.). Prentice Hall. From the original on 2012-01-20. Retrieved 2011-12-10. Chirgwin, Richard (Sep 23, 2012). The Register.
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From the original on 2013-09-29. Retrieved 2013-09-24. 'Erika violet' is RAL 4003, according to 2016-10-18 at the. Similar to Pantone 675U or RGB (196,97,140). Crawford, Dwayne (Sep 11, 2013). From the original on 2014-02-22.
Retrieved Feb 12, 2014. Cabling Installation and Maintenance. May 14, 2017.
From the original on 2019-08-06. Retrieved Aug 6, 2019. ^ Leroy Davis (2007-02-21). From the original on 2007-12-12. Retrieved 2007-12-01. 2016-04-27 at the Retrieved 2016-04-09. (PDF).
(PDF) from the original on 2015-12-03. 2010-08-12 at the (tutorial at lanshack.com) Retrieved 2010-08-20. 2011-06-09 at the. Document 27042.
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Retrieved 2014-01-13. 2016-01-20 at the. Telcordia. 2016-01-20 at the. Telcordia.External links Wikimedia Commons has media related to. The FOA Reference Guide To Fiber Optics.
Coupling Light into Standard Fiber vs. End-Capped Fiber Features. Coreless End Cap Reduces Intensity at Air-to-Glass Interface. One FC/PC Connector with End Cap and AR V-Coating for 1064 nm. One Uncoated FC/APC or Scissor-Cut End. Fiber Type: Single Mode Fiber.
Stainless Steel Tubing, Extra Metal Caps Included. See Handling Tab for Guidelines for High-Power ApplicationsThorlabs offers patch cables with a coreless end cap and an antireflection-coated FC/PC connector on one end. The AR coating provides. Cross Section of Standard Fiber vs. Coreless FiberPrevent Laser-Induced DamageThese patch cables are end-capped with a to protect them from laser-induced damage.
Without an end cap, the beam diameter of light entering or exiting the fiber must match the core size. This can create a high power density at the air-to-glass interface and cause damage when the intensity is beyond the damage threshold. However, the end cap contains no waveguide. Thus, the light path is not confined and can enter or exit the end cap with a larger beam diameter, as shown in the image to the right. This reduces the optical power density at the air-to-glass interface and helps to prevent damage.Custom end-capped patch cables are also available; contact for details. Thorlabs can also manufacture these cables in custom lengths and with certain custom fibers.
Please contact your local Tech Support office for assistance in ordering these items. HandlingIMPORTANT NOTE: Before using these fibers with your equipment, make sure that you are familiar with all operating and safety instructions provided with your light source. Carefully read the below information; proper operation and handling of these devices is imperative to prevent damage to fiber and related equipment.1. Before attaching the provided fibers to your system, inspect both the input and output connector ends.
The end faces should be clean and as free from contamination as possible. If not, clean the ends as outlined in the cleaning section below. Check the fiber ends both before connecting the fiber and also after disconnecting the fiber.
It is very easy for contaminants to be transferred from one connector to another if proper care is not taken.2. To avoid damage to the fibers being used, turn the source off, or reduce the power level to less than 50 mW before attaching the fiber. If any optics have to be aligned, then perform the initial alignment at low power (. Quick LinksLaser-Induced Damage in Silica Optical FibersThe following tutorial details damage mechanisms relevant to unterminated (bare) fiber, terminated optical fiber, and other fiber components from laser light sources.
These mechanisms include damage that occurs at the air / glass interface (when free-space coupling or when using connectors) and in the optical fiber itself. A fiber component, such as a bare fiber, patch cable, or fused coupler, may have multiple potential avenues for damage (e.g., connectors, fiber end faces, and the device itself). The maximum power that a fiber can handle will always be limited by the lowest limit of any of these damage mechanisms.While the damage threshold can be estimated using scaling relations and general rules, absolute damage thresholds in optical fibers are very application dependent and user specific. Users can use this guide to estimate a safe power level that minimizes the risk of damage. Following all appropriate preparation and handling guidelines, users should be able to operate a fiber component up to the specified maximum power level; if no maximum is specified for a component, users should abide by the 'practical safe level' described below for safe operation of the component. Factors that can reduce power handling and cause damage to a fiber component include, but are not limited to, misalignment during fiber coupling, contamination of the fiber end face, or imperfections in the fiber itself.
For further discussion about an optical fiber’s power handling abilities for a specific application, please contact Thorlabs’. Damaged Fiber End Damage at the Air / Glass InterfaceThere are several potential damage mechanisms that can occur at the air / glass interface. Light is incident on this interface when free-space coupling or when two fibers are mated using optical connectors. High-intensity light can damage the end face leading to reduced power handling and permanent damage to the fiber. For fibers terminated with optical connectors where the connectors are fixed to the fiber ends using epoxy, the heat generated by high-intensity light can burn the epoxy and leave residues on the fiber facet directly in the beam path.
Plot showing approximate input power that can be incident on a single mode silica optical fiber with a termination. Each line shows the estimated power level due to a specific damage mechanism. The maximum power handling is limited by the lowest power level from all relevant damage mechanisms (indicated by a solid line).Fibers terminated with optical connectors have additional power handling considerations. Fiber is typically terminated using epoxy to bond the fiber to a ceramic or steel ferrule. When light is coupled into the fiber through a connector, light that does not enter the core and propagate down the fiber is scattered into the outer layers of the fiber, into the ferrule, and the epoxy used to hold the fiber in the ferrule. If the light is intense enough, it can burn the epoxy, causing it to vaporize and deposit a residue on the face of the connector. This results in localized absorption sites on the fiber end face that reduce coupling efficiency and increase scattering, causing further damage.For several reasons, epoxy-related damage is dependent on the wavelength. In general, light scatters more strongly at short wavelengths than at longer wavelengths.
Misalignment when coupling is also more likely due to the small MFD of short-wavelength SM fiber that also produces more scattered light.To minimize the risk of burning the epoxy, fiber connectors can be constructed to have an epoxy-free air gap between the optical fiber and ferrule near the fiber end face. Our use connectors with this design feature. Determining Power Handling with Multiple Damage MechanismsWhen fiber cables or components have multiple avenues for damage (e.g., fiber patch cables), the maximum power handling is always limited by the lowest damage threshold that is relevant to the fiber component. In general, this represents the highest input power that can be incident on the patch cable end face and not the coupled output power.As an illustrative example, the graph to the right shows an estimate of the power handling limitations of a single mode fiber patch cable due to damage to the fiber end face and damage via an optical connector. The total input power handling of a terminated fiber at a given wavelength is limited by the lower of the two limitations at any given wavelength (indicated by the solid lines).
A single mode fiber operating at around 488 nm is primarily limited by damage to the fiber end face (blue solid line), but fibers operating at 1550 nm are limited by damage to the optical connector (red solid line).In the case of a multimode fiber, the effective mode area is defined by the core diameter, which is larger than the effective mode area for SM fiber. This results in a lower power density on the fiber end face and allows higher optical powers (on the order of kilowatts) to be coupled into the fiber without damage (not shown in graph). However, the damage limit of the ferrule / connector termination remains unchanged and as a result, the maximum power handling for a multimode fiber is limited by the ferrule and connector termination.Please note that these are rough estimates of power levels where damage is very unlikely with proper handling and alignment procedures. It is worth noting that optical fibers are frequently used at power levels above those described here. However, these applications typically require expert users and testing at lower powers first to minimize risk of damage. Even still, optical fiber components should be considered a consumable lab supply if used at high power levels.Intrinsic Damage ThresholdIn addition to damage mechanisms at the air / glass interface, optical fibers also display power handling limitations due to damage mechanisms within the optical fiber itself. These limitations will affect all fiber components as they are intrinsic to the fiber itself.
Two categories of damage within the fiber are damage from bend losses and damage from photodarkening.Bend LossesBend losses occur when a fiber is bent to a point where light traveling in the core is incident on the core/cladding interface at an angle higher than the critical angle, making total internal reflection impossible. Under these circumstances, light escapes the fiber, often in a localized area.
The light escaping the fiber typically has a high power density, which burns the fiber coating as well as any surrounding furcation tubing.A special category of optical fiber, called double-clad fiber, can reduce the risk of bend-loss damage by allowing the fiber’s cladding (2nd layer) to also function as a waveguide in addition to the core. By making the critical angle of the cladding/coating interface higher than the critical angle of the core/clad interface, light that escapes the core is loosely confined within the cladding. It will then leak out over a distance of centimeters or meters instead of at one localized spot within the fiber, minimizing the risk of damage. Thorlabs manufactures and sells, which boasts very high, megawatt range power handling.PhotodarkeningA second damage mechanism, called photodarkening or solarization, can occur in fibers used with ultraviolet or short-wavelength visible light, particularly those with germanium-doped cores. Fibers used at these wavelengths will experience increased attenuation over time. The mechanism that causes photodarkening is largely unknown, but several fiber designs have been developed to mitigate it. For example, fibers with a very low hydroxyl ion (OH) content have been found to resist photodarkening and using other dopants, such as fluorine, can also reduce photodarkening.Even with the above strategies in place, all fibers eventually experience photodarkening when used with UV or short-wavelength light, and thus, fibers used at these wavelengths should be considered consumables.Preparation and Handling of Optical FibersGeneral Cleaning and Operation GuidelinesThese general cleaning and operation guidelines are recommended for all fiber optic products. Users should still follow specific guidelines for an individual product as outlined in the support documentation or manual.
Damage threshold calculations only apply when all appropriate cleaning and handling procedures are followed.All light sources should be turned off prior to installing or integrating optical fibers (terminated or bare). This ensures that focused beams of light are not incident on fragile parts of the connector or fiber, which can possibly cause damage.The power-handling capability of an optical fiber is directly linked to the quality of the fiber/connector end face.
Always inspect the fiber end prior to connecting the fiber to an optical system. The fiber end face should be clean and clear of dirt and other contaminants that can cause scattering of coupled light. Bare fiber should be cleaved prior to use and users should inspect the fiber end to ensure a good quality cleave is achieved.If an optical fiber is to be spliced into the optical system, users should first verify that the splice is of good quality at a low optical power prior to high-power use. Poor splice quality may increase light scattering at the splice interface, which can be a source of fiber damage.Users should use low power when aligning the system and optimizing coupling; this minimizes exposure of other parts of the fiber (other than the core) to light. Damage from scattered light can occur if a high power beam is focused on the cladding, coating, or connector.Tips for Using Fiber at Higher Optical PowerOptical fibers and fiber components should generally be operated within safe power level limits, but under ideal conditions (very good optical alignment and very clean optical end faces), the power handling of a fiber component may be increased. Users must verify the performance and stability of a fiber component within their system prior to increasing input or output power and follow all necessary safety and operation instructions.
The tips below are useful suggestions when considering increasing optical power in an optical fiber or component.Splicing a fiber component into a system using a can increase power handling as it minimizes possibility of air/fiber interface damage. Users should follow all appropriate guidelines to prepare and make a high-quality fiber splice. Poor splices can lead to scattering or regions of highly localized heat at the splice interface that can damage the fiber.After connecting the fiber or component, the system should be tested and aligned using a light source at low power.
The system power can be ramped up slowly to the desired output power while periodically verifying all components are properly aligned and that coupling efficiency is not changing with respect to optical launch power.Bend losses that result from sharply bending a fiber can cause light to leak from the fiber in the stressed area. When operating at high power, the localized heating that can occur when a large amount of light escapes a small localized area (the stressed region) can damage the fiber. Avoid disturbing or accidently bending fibers during operation to minimize bend losses.Users should always choose the appropriate optical fiber for a given application. For example, large-mode-area fibers are a good alternative to standard single mode fibers in high-power applications as they provide good beam quality with a larger MFD, decreasing the power density on the air/fiber interface.Step-index silica single mode fibers are normally not used for ultraviolet light or high-peak-power pulsed applications due to the high spatial power densities associated with these applications. Item #Fiber TypeOperatingWavelengthMFD aDamage Threshold (CW)AR Coating bMaxAttenuation cNACladding/CoatingDiameterConnectorsEnd Cap LengthJacketP5-1064HE-2d980 - 1550 nm73 - 91 µm e1 W or 300 mW f≤2.0 dB/km0.13 - 0.15125 ± 1 µm /245 ± 15 µmFC/PC (End Cap) to FC/APC410 ± 30 µm gP9-1064HE-215 WFC/PC (End Cap) to Scissor-Cutand. Mode Field Diameter, Calculated at 1064 nm. Only the FC/PC connector on each patch cable has an AR coating.
Max attenuation is specified for unterminated fiber. Uses Coreless Termination Fiber for End Cap. This MFD is calculated for the end cap. The MFD of the SM980-5.8-125 fiber is 5.7 - 6.4 µm at 1064 nm. If the FC/APC connector is mated to another FC/APC connector, it can handle powers up to 1 W. In a free-space application, the power at the FC/APC connector should not exceed 300 mW. The index for the SM fiber core, calculated at 1064 nm, is 1.4574 (NA 0.15).
The index for the end cap, calculated at 1064 nm, is 1.4496.