Exploring the Anatomy of A Fiber Optic Cable

What’s really inside a fiber optic cable? That’s a question that most customers of fiber optic cable suppliers want to know. Fiber optic is the communications medium that works by sending optical signals down hair-thin strands of extremely pure glass or plastic fiber. Fiber optic cables are capable of carrying high volume of data over long distances. This article is written to take a peek inside fiber optic cables. Starting at the center and working our way outside.

A standard fiber optic cable is comprised of four specific parts:
Core: A fiber optic’s center is made of glass, and this tube carries the cable’s light signals. Depending on the type of fiber optic cable (single more of multimode), the core varies in size. Single mode fibers consist of a tiny glass core that typically has a diameter between 8.3 and 10 microns. This type of cable is used for telephone and CATV with laser sources at 1300 and 1550nm because it has a lower loss and virtually infinite bandwidth. For multi mode fibers, the core is larger. Their core size ranges from 5 to 7 times larger than a single mode core. With a diameter ranging between 50 to 62.5 microns,it supports the transmission of multiple mode (rays) of light and perfect for high data applications. Multimode is generally used with LED source at wavelengths of 850 and 1300nm for slower local area networks (LANs) and lasers at 850 (VCSELs) and 1310nm (Fabry-Perot lasers) for networks running at gigabyte per seconds or more. Multi mode cables are typically used over shorter distances than single mode fiber optic cables.
Cladding layer: The core is surrounded by an optical material called the “cladding” that traps the light in the core using an optical technique called “total internal reflection.” When transmitting data (especially over long distances), light rays can reflect off each other and travel in different directions. The cladding keeps those signals straight.Buffer: Buffer is made to protect fiber from moisture and physical damage. The buffer is what one strips off the fiber for termination or splicing. More often than not, the buffer is made of
Plastic.

Jacket: The fiber optic’s cable exterior is typically made of tough, durable polyurethane. Its job is to protect the overall integrity of the fiber optic cable. The jacket is the first line of defense in a fiber optic cable. Routing cables can put stresses on a fiber optic cable and a jacket sometimes contains an extra layer to avoid these potential hazards.

Water Barrier: Common water barriers for ordinary cable include: an axially laid aluminum foil/polyethylene laminated film immediately inside the polyurethane of polyethylene plastic sheaths;
and/or the use of moisture resistant compounds around the fibers.
If you’d like to purchase or know more informations on fiber optic cable price per foot, you can feel free to contact fiberstore customer service team at sales@fiberstore.com

The Time Of Fiber Optic Cable

People are always looking to keep up with the latest technologies hitting the market in an effort to upgrade communication platform. Fiber optics is far more technologically advanced and quickly replaced copper wires around the world. Fiber optic cables have the advantage of security, efficiency, higher bandwidth, smaller size, low maintenance, withstand harsher conditions, better picture quality, etc. Various types of fiber cables available are single mode cables, multimode cables, duplex cables, simplex cables, bare fiber, large core optical fiber, plastic optical fiber cables, etc.

At the moment, the current trends in the industry are applications such as cloud computing, cloud services and social media causing data volumes to skyrocket. As technology evolves, operators need more complex data centers with the ability to tackle these situations effectively. The flipside is that these constant changes have to be implemented efficiently despite mounting cost pressures. At the same time, planning and implementation cycles are becoming shorter and shorter, demanding an extremely flexible environment. Data center operators need to have profitable solutions that ensure maximum availability, suitability for consolidation, expansion and maximum energy efficiency.

The current trend in passive networking is that we see more companies enquiring about cabling security needs. Today there is a need to reduce costs associated with downtime. Pre-terminated cabling solutions make it easier and quicker to install with less chances of error. Therefore it eliminates the time required for termination and can save valuable time. We’re also seeing increased deployment of Cat7 cable and fiber-optic systems including MPO/MTP solutions(like mpo cable multimode). We believe this will be in line with the growing performance needs of data centers and networks.

In the last few years, Fiber optics are gaining acceptance due to pre-polished connectors, pre- terminated fiber and MPO fiber plug and play connection systems. This leads to a decrease in the complexity of installing fiber cabling. Copper still continues to be used to offer connectivity within a building and to the user’s desk. Presently fiber-optic cabling is being deployed in data centers for achieving higher performance as well as in backbone cabling for connectivity over longer distances such as between different buildings on a campus.

There are many fiber optic cable manufacturers who specialize in single mode, multimode, simple, duplex and multi-strand cables. Several manufacturers provide low cost, quick-turn, high volume fiber cables and fiber cable assembly solutions, for example, Corning company, the corning fiber optic cable is known excellent. It is important to identify the exact requirement of fiber cables whether they would be easy to install, splice or terminate, etc. This is necessary as it ultimately decides the cost of installing the fiber cables. So before order cables, you should always guarantee it with our sales sales@fiberstore.com.

Tight Buffer Cable VS Loose Tube Cable

You may familiar with bulk fiber optic cable, but how much do you know the differences between tight buffer fiber and loose tube cable? This article will focus on tight buffer vs loose tube cable.

tight buffer vs loose tube cable

Tight Buffer vs Loose Tube Cable Design

Tight buffer or tight tube cable designs are typically used for ISP applications. Each fiber is coated with a buffer coating, usually with an outside diameter of 900m.

Loose buffer or loose tube cables mean that the fibers are placed loosely within a plastic tube whose inner diameter considerably larger than the fiber itself. Usually 6 to 12 fibers are placed within a single tube. The interior of the plastic tube is usually filled with a gel material that protects the fibers from moisture and physical stresses that may be experienced by the overall cable. Loose buffer designs are used for OSP applications such as underground installations, lashed or self-supporting aerial installations, and other OSP applications.

Advantages of Tight Buffer vs Loose Tube Cable

Each construction has inherent advantages. The loose buffer tube offers lower cable attenuation from microbending in any given fiber, plus a high level of isolation from external forces. Under continuous mechanical stress, the loose tube permits more stable transmission characteristics. The tight buffer construction permits smaller, lighter weight designs for similar fiber configuration, and generally yields a more flexible, crush resistant cable.

The other fiber protection technique, tight buffer, uses a direct extrusion of plastic over the basic fiber coating. Tight buffer constructions are able to withstand much greater crush and impact forces without fiber breakage.

The tight buffer design, however, results in lower isolation for the fiber from the stresses of temperature variation. While relatively more flexible than loose buffer, if the tight buffer is deployed with sharp bends or twists, optical losses are likely to exceed nominal specifications due to microbending.

Tensile Loading

Cable tensile load ratings, also called cable pulling tensions or pulling forces, are specified under short-term and long-term conditions. The short-term condition represents a cable during installation and it is not recommended that this tension is exceeded. The long-term condition represents an installed cable subjected to a permanent load for the life of the cable. Typical loose-tube cable designs have a short-term (during installation) tensile rating of 600 pounds (2700 N) and a long-term (post installation) tensile rating of 200 pounds (890 N).

Conclusion

Tight buffer vs loose tube cable, each has its own advantages and uses. Nowadays there are many big brands fiber optic cable manufacturers provide tight buffer cables and loose tube cables. FS.COM, also offers a wide range of bulk fiber optic cables, including cables from corning and cables for different applications, bulk fiber optic cable can be made in a variety of lengths and configurations to meet your needs. For more details, please visit FS.COM.

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Size and Weight Advantages of Fiber Optic Cable over Copper Cable

Size and weight factors are always needed to be taken into consideration when preparing for a cable plant installation. Fiber optic cables are now running existing conduits or raceways that are partially or almost completely filled with copper cable. This is another area where small fiber optic cable has advantages over copper cable. In this article, we will do a comparison and try to determine the reduced-size and weight advantages of fiber optic cable that over copper cable.

advantages of fiber optic cable

Advantages of Fiber Optic Cable

As we already know, a coated optical fiber is typically 250um in diameter. We learn that fiber optic ribbon cable sandwich up to 12 coated optical fibers between two layers of Mylar tape. Twelve of these ribbons stacked on top of each other form a cube roughly 3mm by 3mm. This cube can be placed inside a buffer and surrounded by a strength member and jacket to form a cable. The overall diameter of this cable would be only slightly larger than an RG6 coaxial cable or a bundle of four Category 5e cable.

So how large would a copper cable have to be to offer the same performance as the 144 optical fiber ribbon cable? That would depend on transmission distance and the optical fiber data rate. Take Category 5E cable as an example, let’s place a bundle of Category 5e cables up against the 144 optical fiber ribbon cable operating at a modest 2.5Gbps data rate over a distance of just 100m.

A Cat5e cable contains four conductor pairs and as defined in ANSI/TIA-568-B.2 is 0.25” in diameter. Each pair is capable of a 100MHz transmission over 100m. 100MHz transmission carries 200 million symbols per second. If each symbol is a bit, the 100MHz Category 5e cable is capable of a 200Mbps transmission rate. When the performance of each pair is combined, a single Category 5 cable is capable of an 800Mbps transmission rate over a distance of 100m

Now let’s see how many Category 5e cables will be required to provide the same performance as the 144 optical fiber ribbon cable. The 144 optical fiber ribbon cable has a combined data transmission rate of 360Gbps. When we divide 360Gbps by 800Mbps, we see that 450 Category 5e cables are required to equal the performance of this modest fiber-optic system.

When 450 Category 5e cables are bundled together, they are roughly 5.3 inches in diameter. As noted earlier in this chapter, the 144 optical fiber ribbon cable is approximately the size of four Category 5e cables bundled together. The Category 5e bundle thus has a volume of roughly 112.5 times greater than the 144 optical fiber ribbon cable. In other words, Category 5e bundles need 112.5 times more space in the conduit than the 144 optical fiber ribbon cable.

This comparison we just made is very conservative. This distance we used was kept very short and the transmission rate for the optical fiber was kept low. We can get even a better appreciation for the cable size reduction fiber optic cable offers if we increase the transmission distance and the data rate.

In this comparison, let’s increase the transmission distance to 1,000m and the data transmission rate to 10Gbps. The bandwidth of a copper cable decreases as distance increases, just as with fiber-optic cables. Because we have increased the transmission distance by a factor of 10, it’s fair to say that the Category 5e cable bandwidth will decrease by a factor of 10 over 1000m.

With a reduction in bandwidth by a factor of 10, we will need ten times more Category 5e cables to equal the old 2.5Gbps performance. In other words, we need 4,500 Category 5e cables bundled together. In this comparison, however, the bandwidth has been increased from 2.5Gbp to 10Gbps. This means we have to quadruple the number of Category 5e cables to meet the ban width requirement. We now need 18,000 Category 5e cables bundled together. Imagine how many cables we would need if the transmission distance increased to 80,000m. We would need whopping 1,440,000 Category 5e cables bundled together.

These comparisons vividly illustrate the size advantages of fiber optic cable that has over copper per cables. The advantage becomes even more apparent as distances increase. The enormous capacity of such as small cable is exactly what is needed to install high-bandwidth systems in buildings where the conduits and raceways are almost fully populated with copper cables.

Now we have calculated the size advantages of fiber optic cable over Cat5e cable. Let’s look at the weight advantages of fiber optic cable. It is pretty easy to see that thousands, tens of thousands, or millions of Cat5e cable bundled together will outweigh a ribbon fiber optic cable roughly one half of an inch in diameter. It’s difficult to state exactly how much less a fiber optic cable would weigh than a copper cable performing the same job – these are just too many variables in transmission distance and data rate. However, it’s not difficult to imagine the weight savings that fiber-optic cables offer over copper cables. These weight savings are being employed in commercial aircraft, military aircraft, and the automotive industries, just to mention a few.

Conclusion

From the above, we have learned the size and weight advantages of fibre optic cable. FS, a reliable provider of networking equipment, offers a comprehensive line of fiber optic cables and Ethernet cables. Any queation about cabling, please contact us via sales@fs.com.

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How to Calculate Fiber Optic Loss Budget

Fiber optic loss budget calculation is conduct to analysis a fiber optic system’s operation characteristics. It included the items such as routing, electronics, wavelengths, fiber type, and circuit length, attenuation and bandwidth of which are the key parameters for budget loss analysis.

Design of a fiber optic system is a balancing act. As with any system, you need to set criteria for performance and then determine how to meet those criteria. It’s important to remember that we are talking about a system that is the sum of its parts.

Calculation of a system’s capability to perform is based upon a long list of elements. Following is a list of basic items used to determine general transmission system performance:

Fiber Loss Factor – Fiber loss generally has the greatest impact on overall system performance. The fibre optic cable manufacturers provide a loss factor in terms of dB per kilometer. A total fiber loss calculation is made based on the distance x the loss factor. Distance in this case the total length of the fiber cable, not just the map distance.

Type of fiber – Most single mode fibers have a loss factor of between 0.25 (1550nm) and 0.35 (1310nm) dB/km. Multimode fibers have a loss factor of about 2.5 (850nm) and 0.8 (1300nm) dB/km. The type of fiber used is very important. Multimode fibers are used with L.E.D. transmitters which generally don’t have enough power to travel more than 1km. Single mode fibers are used with LASER transmitters that come in various power outputs for “long reach” or “short reach” criteria

Transmitter – There are two basic type of transmitters used in a fiber optic systems. LASER which come in three varieties: high, medium, and low (long reach, medium reach and short reach). Overall system design will determine which type is used. L.E.D. transmitters are used with multimode fibers, however, there is a “high power” L.E.D. which can be used with Single mode fiber. Transmitters are rated in terms of light output at the connector, such as -5dB. A transmitter is typically referred to as an “emitter”.

Receiver Sensitivity – The ability of a fiber optic receiver to see a light source. A receiving device needs a certain minimum amount of received light to function within specification. Receivers are rated in terms of required minimum level of received light such as -28dB. A receiver is also referred to as a “detector”.

Number and type of splices – There are two types of splices. Mechanical, which use a set of connectors on the ends of the fibers, and fusion, which is a physical direct mating of the fiber ends. Mechanical splice loss is generally calculated in a range of 0.7 to 1.5 dB per connector. Fusion splices are calculated at between 0.1 and 0.5 dB per splice. Because of their limited loss factor, fusion splices are preferred.

Margin – This is an important factor. A system can’t be designed based on simply reaching a receiver with the minimum amount of required light. The light power budget margin accounts for aging of the fiber, aging of the transmitter and receiver components, addition of devices along the cable path, incidental twisting and bending of the fiber cable, additional splices to repair cable breaks, etc. Most system designers will add a loss budget margin of 3 to 10 dB

Let’s take a look at a typical scenario where a fiber optic transmission system would be used.

Two operation centers are located about 8 miles apart based on map distance. Assume that the primary communication devices at each center is a wide area network capable router with fiberoptic communication link modules, and that the centers are connected by a fiber optic cable. The actual measured distance based on walking the route , is a total measured length (including slack coils) of 9 miles. There are no additional devices installed along the cable path. Future planning provides for the inclusion of a freeway management system communication link within 5 years.

(Assume that this system will have at least 4 mid-span fusion splices. )

Fiber Loss: 14.5 km × 35dB = -5.075

Fusion splice Loss : 4 × .2dB = -.8

Terminating Connectors : 2 × 1.0dB = -2.0

Margin: -5.0

Total Fiber Loss : -12.875

Because a loss margin of 5.0dB was included in the fiber loss calculation, the short reach option will provide sufficient capability for this system. In fact, the total margin is 8.0db because the difference between the loss budget and receiver sensitivity is 3.0db.

Remember FiberStore provides all the components in the complete fiber optic cable plant, including all the passive and active components of the circuit. As a main fiber optic cable supplier, you can find different designs of cable such as tight buffer, loose tube or even fiber optic ribbon cable, which are manufactured compliant high industry standard and will save your cable plant loss budget largely.