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Corning Optical Fiber Product FAQs

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General

• Where can I find product specifications?

Specifications for all products are available in our product information sheets available on each individual product page.

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Full Spectrum Fibers

• What impact does the absorption in the water peak region have on fiber?

Traditional standard single-mode fibers have attenuation specifications at 1383 nm of up to six times higher than in the original transmission band (O-Band) making them impractical for use in the water peak region.


• What is full-spectrum fiber?

Full-spectrum fiber is the industry term for fiber that can feasibly be used long-term across the full single-mode fiber transmission spectrum due to permanently low attenuation in the E-band (1360-1460 nm) including the 1383 nm water peak, as well as having enhanced attenuation and macrobending specifications in the L-band (1565-1625 nm).  Industry standards organizations have established new classes of standard single-mode fibers that fulfill the full-spectrum requirements.  The most widely recognized examples of such a standard are ITU-T G.652.C and D and IEC 60793-2-50 Type B.1.3.

• What is the “water peak region”?

The water peak is the wavelength region centered on 1383 nm where fiber attenuation is traditionally associated with long-term increase due to the bonding that hydrogen atoms can form with oxygen in the glass structure. The hydrogen atoms can attach to available oxygen sites to form hydroxyl ions (OH-) which absorb light strongly at wavelengths around 1383 nm. The loss due to hydroxyl ion absorption increases by exposure to hydrogen during the operational lifetime of the fiber, an effect known as hydrogen aging.  A full spectrum fiber has been manufactured to resist attenuation increase around 1383 nm due to hydrogen exposure.

• What is the benefit of full-spectrum fibers?

Full-spectrum applications involve simultaneous (WDM) transmission at multiple wavelengths (between 1270 to 1610 nm) over a single fiber. Full-spectrum fibers provide more useable wavelengths (in the E-band and the L-band) than standard single-mode fiber and therefore enable more bandwidth per fiber. Corning ensures proper testing and qualification has been conducted in order to guarantee the attenuation values in the water peak area represent post-hydrogen aging performance for trusted long-term operation at any transmission wavelength.


• Is the 1383 nm attenuation specification the only value to consider in purchasing a full-spectrum fiber?

No. When making a fiber selection, we recommend considering the full set of fiber specifications and the overall value of the fiber supplier. We do not believe it is wise to use a single specification to choose an optical fiber supplier. The use of the water peak region is associated with emerging or future transmission technologies such as Course Wave Division Multiplexing (CWDM) and functional performance is required across the full transmission spectrum. 

Instead of focusing on just one attribute for potential low-water-peak applications, Corning focuses on providing the best overall value to the customer including standard single-mode fiber attributes that provide real, tangible benefits to customers today such as comprehensive environmental specifications for trusted long-term performance, low attenuation at operating wavelengths across the full transmission spectrum and industry leading CPC^® coating enabling excellent performance in the most constrained of cable deployments.

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Multimode Fiber

• What is minEMBc?

MinEMBc is a superior testing procedure that provides a true scalable bandwidth value,
reliably predicting different data rates and link lengths.  Unlike the DMD method, the minEMBc method measures the actual fiber bandwidth performance, recognizing the fact that overall system bandwidth is a function of both the bandwidth properties of the fiber and also the particular characteristics of individual laser sources. The result is reel-specific bandwidth performance values, enabling more system margin and design flexibility.  Corning is committed to providing comprehensive fiber testing, ensuring that every strand of fiber we ship is of the highest quality.  For more information, click here.

• Is 50 µm interoperable with 62.5 µm?

Corning recommends compliance with standards by maintaining consistent core sizes within a multimode fiber cable plant.  In situations where mixing core sizes is unavoidable, it is technically feasible to combine 50 µm and 62.5 µm fiber in a single link using either LED or laser sources.  There are no standardized methods for 50 µm – 62.5 µm interoperability, nor is there a standard remedy for any system impairments that occur.  For further information, click here.

• Is multimode fiber future-proof?

For typical premises links, multimode fiber remains the cost effective solution.  This is due to the fact that in a typical link, the cost of transceivers is ~ 10x the cost of the fiber/cable/connectors.  While single-mode fiber is relatively cheap, it requires the use of costly 1300 nm transceivers which are roughly 2x – 3x the cost of 850 nm multimode transceivers.  By investing a little bit more money in a high-quality, multimode fiber structured cabling system, substantial overall savings can be realized by enabling the use of low-cost transceivers.  As systems migrate to higher bit rates such as 40 GbE and 100 GbE, initial projections show that the transceiver cost savings enabled by multimode fiber will only get bigger. And, as recently demonstrated by Corning, existing OM3 and OM4 multimode fiber can reach the extended link lengths required by premises networks – even at higher speeds such as 40 Gb/s and 100 Gb/s. 

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LEAF® Fiber

• What are the applications for LEAF fiber?

LEAF fiber is ideal for high-data-rate, long-haul and terrestrial networks greater than 200 km operating multiple high-bit-rate wavelength channels in the C and L bands. Other uses include medium-to-long distance single-channel 1550 nm systems for interoffice and long-distance applications.


• What is large effective area?

Large effective area (A_eff) refers to the average area of the fiber in which optical power is transmitted. The larger the A_eff, the more optical power the fiber can handle without susceptibility to non-linear effects. Conventional NZ-DSF's have smaller effective areas, which can limit transmitted optical power.


• What are the benefits of large effective area?

A larger effective area allows more power to be pumped into the fiber, which can be translated into either longer distance between amplifiers, longer system length or higher signal-to-noise ratio, without detrimental non-linear effects.


• What is PMD (Polarization Mode Dispersion)?

PMD is a linear effect caused by asymmetrical properties in an optical fiber that essentially spreads the optical pulse of a signal. Slight asymmetry in any optical fiber causes the modes of the light pulse to travel at slightly different speeds, distorting the signal. LEAF fiber has low PMD, which reduces signal spreading and minimizes signal distortion. LEAF fiber’s low PMD also creates a clear path for future network upgrades to 40 Gb/s.


• What is the difference between LEAF fiber and standard single-mode fiber?

LEAF fiber has lower dispersion than standard single-mode fiber. As a result, LEAF fiber operates with much less dispersion compensation and other components that are required to operate standard single-mode at high-data-rates. LEAF fiber has more flexibility to provide optical add drop multiplexing over standard single-mode fiber.


• How does LEAF fiber enhance a network?

LEAF fiber provides a low cost-per-bit advantage for long-reach transmission at high-bit-rates making your network more powerful and superior. It also allows for greater network flexibility for present and future upgrades. LEAF fiber’s low PMD can enable network designers to increase their network's distance range between 30 and 200% - depending upon other variables/components in the system. This can occur without signal regeneration or PMD compensators, enabling network designers to achieve higher time-division-multiplexed (TDM) rates.

• Who uses LEAF fiber?

LEAF fiber continues to be deployed by carriers worldwide in advanced, high data rate networks. It is the fiber of choice for advanced optical networks that offer greater capacity, flexibility, and long-term profitability. Key LEAF fiber customers to date include Aerie Networks, Argus Telecommunications, AT&T, Broadwing Communications, Cable & Wireless, Carrier1, China Netcom, China Telecom, China Unicom, COLT Telecom Group plc, Communications Authority of Thailand, Eurotunnel, Interoute (I-21 network), Impsat, KG Telecom, LD COM, Level 3 Communications, Inc., NEESCom, Trans Telecom, Williams Communications and 360Networks. LEAF fiber also has been deployed in South America and China, among other parts of the world.


• What is Corning® LEAF® Optical Fiber?

Corning® LEAF® optical fiber is a single-mode non-zero dispersion-shifted fiber with large effective area that is designed for use with both single and multiple-channel dense wavelength division multiplexing (DWDM) systems operating in the C and L Bands. LEAF fiber can carry information at 2.5 and 10 Gb/s, and due to LEAF fiber’s industry leading PMD (polarization mode dispersion) specifications, the product is fully capable at 40Gb/s. This fiber has been developed to meet emerging network design requirements that use high output power erbium-doped fiber amplifiers (EDFAs), raman amplification and multi-channel DWDM technology. LEAF fiber offers significant performance benefits such as higher power-handling capability, higher signal-to-noise ratio, longer amplifier spacing and maximum DWDM channel plan flexibility.


• How many kilometers of LEAF fiber are deployed throughout the world?

Corning® LEAF® optical fiber is the world’s most widely deployed non-zero dispersion shifted fiber.  As of early 2009, we’ve sold over 30 million kilometers of this advanced, high-performance fiber. LEAF fiber is deployed on six of the earth’s seven continents. In fact, the amount of LEAF fiber deployed around the world could stretch to the moon and back dozens of times.

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Vascade® Fiber

• What is the Corning Vascade family of fibers?

Corning Vascade optical fibers include:

• Vascade® R1000 fiber solution
• Vascade® EX1000 fiber
• Vascade® L1000 fiber
• Vascade® LEAF® fiber
• Vascade® LS+ fiber

Vascade optical fibers give you all the advantages of Corning's submarine fiber experience -- from greater distance, capacity and speed, to dispersion management and lowest cost-per-bit advantages. In the harsh undersea environment, you can rely on the guaranteed performance and reliability of Vascade optical fibers. So, whether you need repeatered or unrepeatered optical fiber solutions, choose Vascade optical fibers to take your submarine network further.

• What are the applications for Vascade submarine fibers?

Transoceanic networks, with typical distances of 3,000 to 10,000 kilometers, require a fiber solution with tightly controlled dispersion enabling higher channel counts, longer reach, lower bit error rate, higher information-carrying capacity and design flexibility. Corning Vascade® R1000 fiber solution is designed for this type of network design.

Short-haul undersea networks, designed for typical distances of 100 to 400 kilometers, benefit from longer reach, higher channel counts, greater power-handling capability and excellent cabled characteristics. Festooned networks, a specific type of short-haul application, are becoming a popular alternative to terrestrial networks for countries that are fortunate enough to have some shoreline geography. These "garlands" of optical fiber deployed down a coastline can offer network developers the ability to connect large population centers there with greater ease and affordability than a terrestrial deployment. Vascade® L1000 is designed specifically for this type of application.

• What is a dispersion-managed fiber solution?

Dispersion management is achieved by combining one fiber with positive dispersion and positive slope with a second fiber with a negative dispersion and negative slope. These two fibers are designed so that both the dispersion and the dispersion slope are balanced, such that at the end of the system, the overall dispersion over a wide wavelength range approaches zero. Both fibers can be used in the main transmission cable of a submarine system. This is unlike Corning's other dispersion compensation fibers, which are built as modules to be incorporated in the mid-stage of an optical amplifier. By managing the overall dispersion and offering a near-zero dispersion slope, Vascade R1000 fiber solution enables the use of more channels, a wider bandwidth spectrum and longer system reach than can be achieved using existing submarine fibers.

• Is dispersion-managed fiber easy to splice? 

Splicing Corning Vascade R1000 fiber solution is comparable to splicing any other multi-fiber submarine network. The same splicing equipment currently available in the industry is used to splice Vascade R1000 fiber solution in your network. As with other Corning submarine fiber products, we provide an optimized set of splicer settings to ensure optimal splicing using standard equipment.

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ClearCurve® single-mode fiber

• What is nanoStructures™ technology?

To improve bend performance in optical fiber, the refractive index must be lowered which basically means to change the composition in portions of the fiber.  This can generally be done by changing the materials (new chemical dopants) or material location/distribution. We believe that using dopants does not deliver enough bend performance benefit, while hole-assisted designs have too much compatibility and complexity concerns.

Therefore, we’ve engineered sub-micron-scale features into a controlled mesh configuration in the fiber cladding that delivers dramatic improvement over dopant designs, without all the significant compatibility tradeoffs. You can think of it as a way to “trap” the light into the core of the fiber (where it is supposed to travel) by engineering an additional level of barrier to prevent light from escaping the fiber when it is bent.


• What market need is this addressing? What opportunities will this enable? 

FTTx is the largest worldwide driver for the telecommunications market. Across the globe, more people live in multiple dwelling units (MDUs) such as apartments or condos than any other type of homes. MDUs have been lagging other FTTx deployment due partly to higher installation costs and the desire for improved aesthetics. Recognizing this, Corning applied its nanoStructures-based technology to create a bend-insensitive fiber that enables cable and hardware product solutions that make MDU installations easier, faster, and less costly.


• Is this a standards-compliant product?

We exceed, by order of magnitude, the most stringent bend requirements in ITU-T G.657 while maintaining full compatibility with all legacy single mode standards including ITU-T G652.


• What is the bend performance of this fiber product? How does this performance compare with competitive offerings?

We expect significant (e.g. orders of magnitude) improved performance of the product compared to existing standard single-mode fiber offerings. We also expect to deliver an order of magnitude improvement over chemically-doped products.

ClearCurve^TM fiber is capable of maintaining a maximum 0.1 db loss per turn down to a 5 mm radius at 1550 nm; 0.05 db for 7.5 mm radius, and 0.03 db for 10 mm radius.


• Is ClearCurve fiber low water peak?

Yes. The fiber will be ITU-T Recommendation G.652.D compliant.


• What is the impact to the mechanical reliability of the fiber?

The mechanical reliability of Corning ClearCurve fiber with the nanoStructures design is equivalent to Corning’s other standard fibers as deployed in the field.  

Remember, any bend enhanced fiber only addresses the optical performance at tight bends.  It does not change the mechanical capabilities of the fiber.  This is true for any commercially available telecommunications fiber.


• What is the proof test of the fiber and shouldn’t it be increased due to small bends?

No. The proof test will be 100kpsi to comply with standards. In this application, improving the proof test does not reduce the failure rate in service.  Corning would be happy to work through the analysis with you upon request.

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ClearCurve® multimode fiber

• What applications does this fiber support?

This fiber can be used in any enterprise network such as local area networks, storage area networks and high-speed parallel interconnects for head ends, central offices and data centers that can benefit from superior macrobend performance and improved bandwidth.

• Are you planning to offer this as an OM1 product? (Will you offer this in a 62.5 µm version?)

The multimode fiber market continues to shift from 62.5 µm to 50 µm.  62.5 µm is largely used for upgrades/additions to legacy/installed 62.5 µm systems.  The vast majority of new multimode fiber installs are 50 µm.  For that reason, we have focused our innovation on the 50 µm version – where we believe we can bring the most value to the end user.  Based on very limited market need, there are no plans to offer an OM1/62.5 µm product at this time.

• Is ClearCurve® multimode fiber a standards-compliant product?

Yes it is compliant with the well established ISO/IEC 11801 type OM3 fiber industry standard and will comply with the proposed OM4 standard as soon as it is published. 

• Does ClearCurve® multimode fiber also use nanoStructures™ technology?

This fiber does not use nanoStructures in its fiber design.  Leveraging the tools in our innovation portfolio, we evaluated several options and technologies to improve bend in multimode fiber. Our evaluation determined that while nanoStructures provides superior performance for single-mode fibers, the bend loss problem in multimode fibers requires a different technology.