What are the Recent Trends in Optical Fiber Cable Designs?

This might be an interesting topic of discussion to a few engineers engaged in fiber optic cable design. We don’t intend to provide any mathematical formula used in the fiber optic cable design in this post, but this may show you the trend in optical fiber cable design around the world.

Optical fiber cables with loose tubes are dominant in the European market. Loose tube technology is sophisticated compared to ribbon technology. Loose tubes need excess fiber length inside them in order to withstand temperature and mechanical effects. Excess fiber length or in short EFL is the key to loose tube technology. Controlling the excess fiber length in a loose tube is a skillful job. The theoretical calculation can guide the engineers to set the pay-off and take-up tensions, water trough temperatures, etc, but the practical manufacturing conditions are important factors to decide the excess fiber length. These may be different from factory to factory and needs optimization. This optimization requires analytical skills.

The inner diameter and therefore outer diameter of the loose tube was depending on the control of excess fiber length. Fiber cable manufacturing machine makers have come up with solutions to control excess fiber length in a loose tube. The outer diameter of a loose tube containing 12 fibers was around 3.0mm and the inner diameter was 2.0mm some years back. It was brought down to 2.5mm and 1.7mm respectively in an attempt to reduce the cable diameter and cable cost. For many years, 2.5mm was the standard loose tube size in many parts of the world. The last 10 years record shows that many cable manufacturers dared to experiment towards lower size loose tubes. Due to these efforts, 12 fibers loose tube size was brought down to around 2.2mm.

The development of microduct cables encouraged fiber optic cable manufacturers to further experiment with the lower sizes of loose tubes. In microduct cables, 12 fibers are put into a loose tube having an outer diameter of approximately 1.5mm and the inner diameter of approximately 1.1mm. Such a smaller size has been achievable with the support of machine suppliers. What is required is a small capstan in a loose tube line between the extruder and wheel capstan to control the excess fiber length.

Reduced size fiber optic cables become practically possible with the help of a small capstan or any other device to control the excess fiber length. The mechanical performances of the small size cables will not be equal to that of the big size cables. Smaller size cables require lesser force to install and therefore the required pulling strength will also be less. The changes towards lower sizes save material, manufacturing, and installation cost.

East Asian markets where ribbon technology is dominant followed basically the concept of reduced sizes of fiber optic cables. For example in Japan, NTT has driven research in fiber optic cable manufacturing facilities to use underground ducts to accommodate a maximum number of cables. The reduced slotted core diameter and development of thin ribbons made it possible to achieve smaller sizes for ribbon slotted core cables also. With NTT’s installation techniques a duct having 75mm outer diameter can accommodate 3 ribbon cables of 1000 fibers. This means 3000 optical fibers in a 75mm duct!

Recent trends show the development of smaller size cables around the world. If you have not still decided to develop smaller size cables, it is not too late. Smaller size cables will present severe competition in the tenders, where conventional cable makers will face threats. Responsible cable design engineers must put their efforts towards change in the design to reduce the cable cost.

Guide to Several Materials in Fiber Optic Cable Construction

Fiber optic cable is considered as one of the most effective transmission medium today for safe, and long-reach communications, and it also offers a number of advantages over copper. In general, fiber optic cable consists of a core, cladding, coating, strengthening fibers, and a cable jacket, which has been clearly introduced in the previous article. Today’s article will focus on the several materials in fiber optic cable construction, as well as their features and applications.
PVC (Polyvinyl Chloride)
Polyvinyl Chloride (PVC) is one of the most commonly used thermoplastic polymers in the world. The PVC cable is typically used for patch connections in the data center, wiring closet, and at the desktop. PVC is produced in two general forms, first as a rigid or unplasticized polymer (RPVC or uPVC). The following image shows a ST single-mode pre-Terminated cable (0.9mm PVC Jacket).
Features:
Good resistance to environmental effects. Some formulations are rated for -55 to +55.
Good flame retardant properties. Can be used for both outdoor and indoor fiber optic cables.
PVC is less flexible than PE (Polyethylene).
PE (Polyethylene)
Polyethylene is a kind of polymer that commonly categorized into one of several major compounds of which the most common include LDPE, LLDPE, HDPE, and Ultrahigh Molecular Weight Polypropylene. Polyethylene fiber has a round cross section and has a smooth surface. Fibers made from low molecular weight polyethylene have a grease like handle.
Features:
Popular cable jacket material for outdoor fiber cables
Very good moisture and weather resistance properties
Very good insulator
Can be very stiff in colder temperatures
If treated with proper chemicals, PE can be flame retardant.
Kevlar (Aramid Yarn)
The word Aramid is a generic term for a manufactured fiber in which the fiber forming substance is a long chain synthetic polyamide in which at least 85% of the amide linkages are attached directly to the two aromatic rings as defined by the U.S. federal trade commission. Kevlar fiber is based on poly (P-phenylene terephthalamide). Aramid yarn is the yellow fiber type material found inside cable jacket surrounding the fibers. It can also be used as central strength members.
Features:
Aramid yarn is very strong and is used in bundle to protect the fibers.
Kevlar is a brand of aramid yarn. Kevlar is often used as the central strength member on fiber cables which must withstand high pulling tension during installation.
When Kevlar is placed surrounding the entire cable interior, it provides additional protection for the fibers from the environment.
Steel Armor
The steel armored fiber cable, using light-steel tube, can provide maximum bend radius, strong protection and flexible cabling. Steel armor jacket is often used on direct burial outdoor cables and it provides excellent crush resistance and is truly rodent-proof. Since steel is a conductor, steel armored cables have to be properly grounded and loss fiber optic cable’s dielectric advantage. Armored fiber optic cable are often used in the outdoor direct burial cables and for the industrial environment where cables are installed without conduits or cable tray protection. The following image shows a single-mode armored fiber optic cable.
Various types of these light-steel armored fiber cables are in stock in fiber-mart.COM, including pre-terminated armored fiber patch cables, armored fiber trunk cables and field-terminated armored fiber cables for both indoor and outdoor applications.
Features:
Provides excellent crush resistance for outdoor direct burial cables
Protects cables from rodent biting
Decreases water ingress into the fiber which prolongs the fiber cable’s life expectancy
Central Strength Member
Strength member is used to increase the tensile force that will be applied on the cable during installation. Strength member will take the pulling force and will keep the fibers safe during installation. For large fiber count cables, a central strength member is often used.
The central strength member provides strength and support to the cable. During fiber optic cable installation, pulling eyes should always be attached to the central strength member and never to the fibers. On fiber splice enclosure and patch panel installations, the cable central strength member should be attached to the strength member anchor on the enclosure or patch panel.
Conclusion
When you choose to use which type of the fiber optic cables, the fiber optic cable construction, along with the mechanical and environment requirements should all be taken into account. All the above materials in the fiber optic cable construction are specifically required to meet the network infrastructure. fiber-mart.COM fiber optic cables come in various types with detailed specifications displayed for your convenient. These quality cables are designed with best-in-class performance. For more information about fiber optic cables or patch cords, you can visit fiber-mart.com.

Guide to Several Materials in Fiber Optic Cable Construction

Fiber optic cable is considered as one of the most effective transmission medium today for safe, and long-reach communications, and it also offers a number of advantages over copper. In general, fiber optic cable consists of a core, cladding, coating, strengthening fibers, and a cable jacket, which has been clearly introduced in the previous article. Today’s article will focus on the several materials in fiber optic cable construction, as well as their features and applications.
PVC (Polyvinyl Chloride)
Polyvinyl Chloride (PVC) is one of the most commonly used thermoplastic polymers in the world. The PVC cable is typically used for patch connections in the data center, wiring closet, and at the desktop. PVC is produced in two general forms, first as a rigid or unplasticized polymer (RPVC or uPVC). The following image shows a ST single-mode pre-Terminated cable (0.9mm PVC Jacket).
Features:
Good resistance to environmental effects. Some formulations are rated for -55 to +55.
Good flame retardant properties. Can be used for both outdoor and indoor fiber optic cables.
PVC is less flexible than PE (Polyethylene).
PE (Polyethylene)
Polyethylene is a kind of polymer that commonly categorized into one of several major compounds of which the most common include LDPE, LLDPE, HDPE, and Ultrahigh Molecular Weight Polypropylene. Polyethylene fiber has a round cross section and has a smooth surface. Fibers made from low molecular weight polyethylene have a grease like handle.
Features:
Popular cable jacket material for outdoor fiber cables
Very good moisture and weather resistance properties
Very good insulator
Can be very stiff in colder temperatures
If treated with proper chemicals, PE can be flame retardant.
Kevlar (Aramid Yarn)
The word Aramid is a generic term for a manufactured fiber in which the fiber forming substance is a long chain synthetic polyamide in which at least 85% of the amide linkages are attached directly to the two aromatic rings as defined by the U.S. federal trade commission. Kevlar fiber is based on poly (P-phenylene terephthalamide). Aramid yarn is the yellow fiber type material found inside cable jacket surrounding the fibers. It can also be used as central strength members.
Features:
Aramid yarn is very strong and is used in bundle to protect the fibers.
Kevlar is a brand of aramid yarn. Kevlar is often used as the central strength member on fiber cables which must withstand high pulling tension during installation.
When Kevlar is placed surrounding the entire cable interior, it provides additional protection for the fibers from the environment.
Steel Armor
The steel armored fiber cable, using light-steel tube, can provide maximum bend radius, strong protection and flexible cabling. Steel armor jacket is often used on direct burial outdoor cables and it provides excellent crush resistance and is truly rodent-proof. Since steel is a conductor, steel armored cables have to be properly grounded and loss fiber optic cable’s dielectric advantage. Armored fiber optic cable are often used in the outdoor direct burial cables and for the industrial environment where cables are installed without conduits or cable tray protection. The following image shows a single-mode armored fiber optic cable.
Various types of these light-steel armored fiber cables are in stock in fiber-mart.COM, including pre-terminated armored fiber patch cables, armored fiber trunk cables and field-terminated armored fiber cables for both indoor and outdoor applications.
Features:
Provides excellent crush resistance for outdoor direct burial cables
Protects cables from rodent biting
Decreases water ingress into the fiber which prolongs the fiber cable’s life expectancy
Central Strength Member
Strength member is used to increase the tensile force that will be applied on the cable during installation. Strength member will take the pulling force and will keep the fibers safe during installation. For large fiber count cables, a central strength member is often used.
The central strength member provides strength and support to the cable. During fiber optic cable installation, pulling eyes should always be attached to the central strength member and never to the fibers. On fiber splice enclosure and patch panel installations, the cable central strength member should be attached to the strength member anchor on the enclosure or patch panel.
Conclusion
When you choose to use which type of the fiber optic cables, the fiber optic cable construction, along with the mechanical and environment requirements should all be taken into account. All the above materials in the fiber optic cable construction are specifically required to meet the network infrastructure. fiber-mart.COM fiber optic cables come in various types with detailed specifications displayed for your convenient. These quality cables are designed with best-in-class performance.

How Should I Terminate My Fiber Optic Cable

In today’s day and age, we are more connected than ever. And we expect it.
At the work place we are attending virtual trainings on the latest technologies and we are connecting across the globe with our colleagues in real-time meetings – with just the click of a button.
When we leave work, we are going home using app-based scooters and bicycles that only needs the swipe of a cell phone. And if taking a highway home, you no longer search for change at a toll booth but instead you drive through a toll lane that scans and charges your account as you drive underneath it.
And it doesn’t stop at home. We are answering emails, while streaming Ultra HD video on our smart TV’s, all while having the latest super hero flick downloading on our tablet to watch on an upcoming business trip.
With the ever-increasing demand for the bandwidth needed to meet today’s expectations; how we design, install, and maintain our fiber optic networks must evolve with that same demand. In particular, the methods used to terminate, or connect, the ends of our fiber optic networks has evolved in the past 20 years quite drastically; starting with hand-polishing a ferrule with films and epoxies to achieve a finished termination. Hand epoxy polishing gave you a good, epoxy-cured connection but can be time consuming, and it took certain skill sets to achieve a good ferrule polish. Epoxy terminations lead to Mechanical Terminations which is the mechanical mating of fibers with the use of specific hand tools, v-groove alignment, and index matching gel to bridge the air gap between fibers. The benefits of using a factory-polished ferrule and the mechanical termination offered a time saving from traditional hand-polishing and allowed even some of the most novice of technicians the ability of putting a quality connector on in the field. As optical fusion splice machines and fusion splicing technology improved, technicians can now fusion splice a pigtail, a length of cable factory terminated on a single end, to a field cable that has been newly pulled or an old cable that needs to be repaired.
More importantly than any convenience of use though, is the performance of the termination. To enjoy some of the luxuries of connectivity mentioned before, we need a stronger optical signal to go farther than ever. Insertion Loss (IL) is a measurement of the optical power that is lost through a mated pair in decibels (dB). To compare the performance in IL of the three main termination methods, hand epoxy can typically range from .20dB – .75dB depending on installer. A typical mechanical style termination IL is 0.50dB, with loss accumulating from both the air gap of a mated pair, and the alignment of the fiber stub to your field fiber. Fusion splicing a pigtail or connector, is going to give your lowest loss of light through termination. Average fusion splice termination IL is .02dB – .05dB of loss through the splice, for a total of typical .20dB IL from your termination. By fusion splicing a connector in your network you are performing that much better in regards of your signal getting from source to receive.
Another important factor of your termination is how much light it reflects, you do not want your termination to be reflective. Reflectance is measured by how much light (dB) is returned back up the link, and the lower the number (farthest from 0) the better. The ferrule of your termination is the main factor in reflectance, and is categorized in 3 main stages: Physical Contact (PC), Ultra Physical Contact (UPC), and Angled Physical contact (APC). To throw a lot of numbers and letters around, PC polish typically has a reflectance of -30dB, UPC polish typical -40dB, and APC polish -65dB or better. Remember, the lower the number the least amount of reflection, so APC being -65dB is premium performance for optical termination because it returns the least amount of light per termination. Hand polishing connector does rely on skill, an experienced technician will be able to give you the best results but it still can be an imperfect science. Mechanical connectors allowed anybody to be able to put on a connector with the use of specific tools and simple termination procedures, but because of the reflectance of the matching gel, along with the mating of the ferrules, you will achieve around the -40dB referenced above. By being able to fusion splice a factory terminated pigtail to a field fiber, you achieve maximum performance of the ferrule polish due to the low reflectance fusion splice technology. A -65dB return loss on an APC termination is possible because a typical core alignment fusion splice is actually considered a non-reflective event. As we bring fiber closer and closer to the home, with lab environment transmission of 400gB of data over fiber, we can’t afford the return of light that our networks of days past allowed us.
With fusion splicing becoming the termination method of choice for performance, it’s now about installation and how we can make it easier. Pigtail splicing while practical, can be cumbersome with cable management and could require more rack space for that management. You prep your field fiber, you prep your pigtail, you splice them together and manage the slack, and you have a high performing termination.
The industry is now seeing Splice on Connectors as a popular choice of termination vs traditional pigtails because of the cost, space, and time savings they offer. Now you can use a factory terminated connector that can be spliced right at the end of your trunk cable, allowing a time savings in cable prep, a space saving without the excess length of traditional pigtails, and still giving your connection an Insertion Loss as low as .20dB, and a minimal return loss as low as -65dB. Splice on Connectors can arguably be your lowest cost, easiest to install, and best performing termination method.
In conclusion, I want to say that I am writing on my laptop while streaming a basketball game, my wife is streaming her reality TV while scrolling home improvement blogs on her phone, and our demand for bandwidth isn’t slowing down. As our use of technology evolves, so must our data networks. And in terms of how we terminate our fibers, the practice of using splice on connectors has us all trending in the right direction.

What Are Some of the Different Fiber Optic Cable Jacket Ratings

There are several parts that make up a fiber optic cable; starting with the core, to the cladding, followed by the coating, the strength member and lastly the outer jacket. The outer jacket is the cover that gives protection and shielding, especially to the optical fibers. Whether it is meant to be indoor/outdoor, UV rated or armored, the jacket is what keeps the fiber protected and useful. Above all of these, the outer jacket is the first layer of protection to the fiber so it can withstand different conditions such as fire, moisture, chemicals, and stress during installations and maneuvering.
The National Electrical Code (NEC) has a classification system for optical fiber cables. The system specifies the requirements regarding how the fiber cables will endure under fire conditions. These requirements concentrate on how these cables can add a dangerous amount of fuel and smoke and transmit fire from one place to another.
Plenum
OFNP – Optical Fiber Non-conductive Plenum – refers to the specific fire code rating of cable that is flame resistant and emits the least toxic fumes or smoke when burned. Plenum rated cables have a higher fire rating and are for both commercial and residential use. They are considered the safest rated cable among jacket types. These cables are primarily used in ducts or pathways for heated and cooled return airflows. These spaces are usually above a ceiling or below a floor that serves as heated or cooled inhabited areas.
Plenum cables are purposely built with a jacket that gives off low amounts of smoke and that is flame retardant. Being able to deter the spread of flames and toxic fumes are the main uses for this jacket rating. The word plenum refers to the space in which air is circulated by a HVAC system. Drop ceilings and raised floors are perfect for the application. Plenum cables still use PVC (Polyvinyl Chloride) in the construction of the plenum jacket but special additives are put into the jacket material in order to make it more flame retardant. The NEC defines plenum cables by the airspace they are put into. Plenum rated cables are often used in building construction, typically they are used as communication cables for the building’s computer and telephone networks. Use of plenum areas for cable does pose some hazard in the event of a fire. This is because there are fewer barriers to contain smoke and flames.
Riser
OFNR – Optical Fiber Non-conductive Riser – is constructed of PVC and will emit toxic fumes when burned. Riser cables are to be run only in non-plenum areas. Plenum can usually replace riser but riser cannot replace plenum. Riser rated cables are typically used in the riser areas of buildings and in vertical telecommunications infrastructures. They connect from one floor to another and are used within shafts in accordance with section 800.53(B) of the NEC (National Electrical Code). They typically have load bearing strength members since they need to be upright without placing added stress on the fiber.
OFNR cable is resistant to oxidation and degradation but still gives off heavy black smoke and toxic gases when it is burned. Yet it is perfectly fine to use as a patch cord or for single in-wall runs. If you want to use it in a building, the building must feature a contained ventilation system and have good fire exits. Location is extremely important for these types of cables.
LSZH – Low Smoke Zero Halogen
These types of cables are made with halogen free materials and although they still emit smoke it is a much safer alternative. This type of cable jacket has superior safety characteristics. This rating offers low smoke, low toxicity and low corrosion standards. Tunnels, enclosed rooms, aircraft, and other minimum-ventilation areas are prime spots for the use of LSZH cables because areas like these are more difficult to escape from quickly. There are many different types of LSZH jacketed fiber optic cables provided for many different uses. The primary use for these types of cables is to satisfy the need for safety and environmental protection. Hospitals, schools and airports are good examples of where these cables should be installed. Due to the amount of people and the serious need for the protection of those people and equipment from toxic matter and gases should a fire ever occur. These cables are especially popular outside the United States, specifically for plenum spaces. Although it may seem as if you can replace plenum with LSZH cables, that’s not really the case. The difference is that while there is a lower smoke rating for LSZH, plenum cables have higher fire spread rating.
Cable tray rated
Tray cables are designed for just that, installation in cable trays. Primarily they are used in industrial control systems, factories, wind turbines and other severe environments. They can be rated for use indoors, outdoors, and in corrosive areas, for hazardous locations or high electrical noise areas. This cable was first introduced in order to combat failures in power and communication applications. There are several different kinds of cables to choose from, these include: Tray Cable (TC), Power Limited Tray Cable (PLTC), Instrumentation Tray Cable (ITC), Exposed Run (ER), and Wind Turbine Tray Cable (WTTC). Effective in direct sunlight as well as underground, these types of cables are extremely versatile in their application. Although cable in tray is viewed as being exposed to a greater risk of mechanical damage and it can be a potential ignition source or fuel load in a fire scenario. Due to this the NEC has a specific requirement in order to ensure the safety and quality of these fiber runs.
When choosing a jacket rating it is important to understand the placement and application where the cables will be run. It is pivotal that the cables meet local code requirements for the installations as well. These ratings are designed to prevent hazards and reduce risks to human and environmental health. We put on a jacket to prevent uncertainties from happening to our body, such as a cold or the flu. Fiber optic cable jacketing is very similar in the sense that we apply a certain compound to prevent a dangerous mishap, or if it does happen in the environment of the application.
Winter is coming… be sure to put on the appropriate jacket! .

What’s the Difference Between Fiber Optic Cabling and Others?

by http://www.fiber-mart.com

If you’re looking at high-speed internet options and find that fiber optic cable is available in your area, you may not understand the differences. fiber optic cablingAfter all, the cables look similar, and they install similarly from the lay-person’s perspective. Generally, that is where the similarities end.
Inside the Cable
Standard cable is known as coaxial cable. If you looked inside, you will find a central, copper core surrounded by insulation wrapped in twisted copper or metal wires before being covered in a plastic jacket. This is the same cable that comes into your house if you have cable television. It’s easy to run and shorten and connect to outlets and televisions. The cable is available in many different lengths and is nearly ubiquitous…plenty of homes have at least one coaxial cable sitting around.
Fiber optic cable, on the other hand, is built a bit differently, and high density fiber optic cables are very complex inside and can transmit a lot of data. High density fiber optic cables won’t come into your home, but if you have fiber optic internet, your home will connect to one of these cables. Fortunately, they work on the same principle…high density just has more protected cables inside, like lanes in a freeway.
The central core of a fiber optic cable is made of tiny strands of glass or plastic known as optical fibers. A single cable can have a few strands or as many as several hundred. Directly coating the strands is something known as cladding…which directs the signal down the strand to increase the distance of cabling that can be used before a repeater (a device that receives the signal on one end and retransmits it on the other to prevent data loss) is required. Then, just like coaxial cable, it contains insulation and a protective jacket.
The difference between these two cables is that one transmits an electromagnetic signal (coaxial) and one transmits light (generally LEDs or lasers).
What Does This Mean for the Consumer?
While standard, coaxial cable internet is available in nearly every urban and suburban area, fiber optics are just rolling out. It can be difficult to find a fiber optic internet provider if your city’s infrastructure or local cable provider hasn’t invested to have fiber optic cabling run to near your house.
Because fiber optics requires less repeaters and other equipment, and cost less to maintain, fiber optic cabling tends to cost less to the consumer than traditional cable internet does. Fiber optics are also much faster than traditional high speed internet because the optical threads have the capacity for greater bandwidth, and fiber optic cable weighs less because it requires less insulation and jacketing.
You can also feel good that fiber optics are more eco-friendly than traditional coaxial cables. Not only does it generate less heat at data centers to use fiber optic cable, but fiber optic cables require less insulation and jacketing, which often involve heavy metals, which can leach into the environment.
Fiber optics are also more secure than traditional coaxial cables. It’s more difficult to tap fiber optic cables because it requires special tools and receivers. Attempting to tap into the system is more likely to just disrupt the system, providing no benefit. Also important to note that information transmitted via pulses of light do not transmit electricity, which makes it harder to “listen” and intercept data from fiber optic cabling systems.