Category: Fiber Optic Cable

A Comparison Of Multimode And Single Mode Cables

Over the past few years, fiber optic cable has become more affordable and widely used. Fiber is ideal for high data-rate systems such as FDDI, multimedia, ATM, or any other network that requires the transfer of large, time-consuming data files. And the basic cables are multimode optic cable and single mode fiber.

A Comparison Of Multimode Cables And Single Mode Cables

Multimode cables have a larger core diameter than that of singlemode cables. This larger core diameter allows multiple pathways and several wavelengths of light to be transmitted. Singlemode Duplex cables and Singlemode Simplex cables have a smaller core diameter and only allow a single wavelength and pathway for light to travel. Multimode fiber is commonly used in patch cable applications such as fiber to the desktop or patch panel to equipment. Multimode fiber is available in two sizes, 50 micron and 62.5 micron. Singlemode fiber is typically used in network connections over long lengths and is available in a core diameter of 9 microns (8.3 microns to be exact).

Most building cables had 62.5/125 micron multimode fibers for LANs or security systems, while outside plant cables were all single-mode fiber. For some time, we have been encouraging people to install hybrid cables with both multimode fibers for today and single-mode fibers for the future regardless of the fiber optic cable price.

If you are transmitting from a smaller fiber core to a larger one, it is not a problem since the larger fiber like large core optical fiber will collect all the light from the smaller one with minimal loss. But if you transmit light from a larger fiber to a smaller one, the light in the larger core will overfill the smaller core and large losses will occur. How big are the losses we are talking about? Coupling a multimode fiber to a single-mode fiber will cause about 20 dB loss. Connecting a 62.5 fiber to a 50 micron core fiber will cause 2 to 4 dB loss, depending on the type of source (laser or LED). In any case, it can be enough loss to prevent network equipment from working properly.

Both 50 micron and 62.5 micron multimode fibers have the same cladding diameter and can use the same connectors and termination processes, but testing still requires using the correct matching fiber optics patch cords or the measured loss will be too low by a few tenths of a dB in one direction (50 to 62.5), or 2 to 4 dB too high the other way (62.5 to 50.)

Needless to say, these mismatched fiber losses affect the end user the same way they affect the installer, creating excess connection loss that can cause systems to malfunction or have high error rates, causing an expensive and annoying service call. Unfortunately, there is no optical mating adapter that will match two dissimilar fibers—although it has been tried many times. There is no solution other than preventing mismatched fiber terminations.

Fiber Resistant LS0H Cables

With the increased demand for safety in public areas and buildings, contractors are now being advised to install materials thar are zero halogen cables to peoples in case of fire. It is now understood that smoke and poisonous fumes can be a greater risk to lives than that of fire alone.

What is Resistance to Fire?
Resistance to fire is the property of a material of assembly to withstand fire or give protection from it and it is measured as the time a product can mantain a level of functionality during a fire.

Fire resistance may be built-in both structurally and by the correct choice and application of building materials. The resistance-to-fire (of a cable) is the term used to describe how long a cable continues to operate in a fire. This may be of primary concern, for instance, in life safety of fire fighting installations.Cable resistance to fiber concerns: the ability of a cable to maintain functionality during fire; the duration of survival in working condition.

To be assured you are buying a cable that will offer security during fire, it must pass 3 tests pertaining to halogen content, low smoke density and flame propagation. The resistance-to-fire performance of cable is indicated in term of survival time which are 15, 30, 60, 90 and 120 minutes of operation in a standardized fire condition at European Level and equipment international (IEC). Local standards and customers specs include their own requirements witch are achieved as well by FiberStore local or tailor-made products.

Fiber-retartant, low smoke halogen free cable (LSZH) and wire has been commercially available fro shipboard applications since the 1970S, offshore marine platforms, rapid transit and similar applications where people are present in confined areas. When worked with other fiber prevention and suppression practices, fire-retardant LSZH cables can help minimize fire-rated deaths and property damage. However, gases produced by all burning materials – whether LSZH or not – are extremely toxic.

Advantages and Disadvantages of LS0H cables

Pro: LSZH wire and cable produces less smoke when burned, which permits people to exit a burning building more quickly and results in less damage.

Con: Because LSZH is more susceptible to jacket cracking caused by pulling lubricants or cable bending, special lubricants has been developed to minimize cable damage during installation.

Pro: Because LSZH releases little or no halogen gas when burned, it reduced the damages to the human respiratory system if inhaled and contributes to less corrosion damage to equipment near the fire.

Cons: LSZH jacket compounds usually have very high filler content to provide the required flame and smoke performance. As a result, most have poorer mechanical, chemical resistance, water absorption and electrical properties than non-LSZH compounds.

Pro: LSZH jackets have a lower coefficient of friction than some non-LSZH jackets, which can make installatin easier.

Cons: The current generation of LSZH cables has not yet established a proven history of long-term performance.

Construction Design And Jacket Materials Of A Cable

Fiber optics has high bandwidth and can transmit data over longer distances. Turn to buy fiber optic cable, you may confused as  there are so many types of cables and it’s difficult to  figure them out. An optical fiber cable consists of a center glass core surrounded by several layers of protective material. The outer insulating jacket is to prevent interference. The construction design and choices of materials are vital in determining characteristics of a cable. The design factors for some types of fiber optic cables are listed below.

Indoor cables– Fire safety is the number one factor in selecting indoor cables, particularly those that run through plenum spaces. Indoor cables must pass the flame-retardant and smoke-inhibitor ratings specified by NEC.

Outdoor cables– Moisture resistance and temperature tolerance are the major factors when choosing materials for outdoor environment cables, like waterproof cables and outdoor cables do. They also need to be ultraviolet (UV) resistant.

Aerial/Self-Supporting Cables– Aerial cables must endure extreme temperature ranges from sunlight heat to freezing snow. They also must survive high wind loading.

Cable Jacket Materials

Polyethylene (PE). PE (black color) is the standard jacket material for outdoor fiber optic cables. PE has excellent moisture – and weather-resistance properties. It has very stable dielectric properties over a wide temperature range. It is also abrasion-resistant.

Polyvinyl Chloride (PVC). PVC is the most common material for indoor cables, however it can also be used for outdoor cables. It is flexible and fire-retardant. PVC is more expensive than PE.

Polyvinyl difluoride (PVDF). PVDF is used for plenum cables because it has better fire-retardant properties than PE and produces little smoke.

Low Smoke Zero Halogen (LSZH) plastics. LSZH plastics are used for a special kind of cable called LSZH cables. They produce little smoke and no toxic halogen compounds. But they are the most expensive jacket material.

Typical fiber cables are made from silica glass, which causes refractions that delay the signal. The standard line is that fiber optic networks transfer data at the speed of light. But in reality, light travels about 31 percent slower through fiber optical cables than it does through a vacuum. But that’s changing, researchers at University of Southampton in England have found a way to build cables that work at 99.7 percent of the speed of light in a vacuum. The researchers’ solution — is a hollow cable with special walls to prevent refraction. They call it an “ultra-thin photonic-bandgap rim”.

Several recent breakthroughs in fiber optics research. For example, scientists at AT&T Labs-Research announced a new record in speed/distance through standard bulk fiber optic cable. And a DARPA-backed team at IBM has found a way to cut the energy use of short-distance fiber optics for supercomputing while doubling the speed.

Bulk Fiber Optic Cabling System

Fiber optic cables are designed for long distance and high bandwidth (Gigabit speed) network communications. Bulk fiber optic cables carry communication signals using pulses of light. While relative expensive, these cables are increasingly being used instead of traditional copper cables, because fiber offers more capacity and is less susceptible to electrical interference. So-called Fiber to the Home (FTTH) installations are becoming more common as a way to bring ultra high speed Internet service (100 Mbps and higher) to residences.

Copper cabling uses electricity to transmit signals from one end to another, bulk fiber optic cable uses light pulses to accomplish the same purpose. The fiber optic cable is made of a transparent glass core surrounded by a mirror like covering called cladding. Light passes through the fiber optic cable, bouncing off the cladding until it reaches the other end of the fiber channel – this is called total internal reflection. As fiber-optics are based entirely on beams of light, they are less susceptible to noise and interference than than other data-transfer mediums such as copper wires or telephone lines. In today’s high speed networks, Graded Index Multimode fiber or Step Index Single mode fiber cable is used to improve light transmission over long distances. Multimode fiber optic cable has a larger core like large core fiber and is typically used in short runs within buildings. Single mode fiber optic cable has a smaller core and is used in long distance runs typically outside between buildings.

While fiber optic cables have so many advantages and widely used in today’s communication. You should take in mind that fiber optic cables are fragile. Fiber cable can be pulled with much greater force than copper wire if you pull it correctly. Just remember following rules:

Do not pull on the fibers. The fiber optic cable manufacturers give you the perfect solution to pulling the cables, they install special strength members, usually Kevlar cutter or a fiberglass rod to pull on. Use it! Any other method may put stress on the fibers and harm them. Most cables cannot be pulled by the jacket. Do not pull on the jacket unless it is specifically approved by the cable manufacturers and you use an approved cable grip.

Do not exceed the maximum pulling load rating. On long runs, use proper lubricants and make sure they are compatible with the cable jacket. On really long runs, pull from the middle out to both ends. If possible, use an automated puller with tension control or at least a breakaway pulling eye.

Do not exceed the cable bend radius. Fiber is stronger than steel when you pull it straight, but it breaks easily when bent too tightly. These will harm the fibers, maybe immediately, maybe not for a few years, but you will harm them and the cable must be removed and thrown away!

Do not twist the cable. Putting a twist in the cable can stress the fibers too. Always roll the cable off the spool instead of spinning it off the spool end. This will put a twist in the cable for every turn on the spool! And always use a swivel pulling eye because pulling tension will cause twisting forces on the cable.

Check the length. Make sure the cable is long enough for the run. It’s not easly or cheap to splice fiber and it needs special protection. Try to make it in one pull, possible up to about 2-3 miles.

Fiber Optic Cables Installer Guidance

Nowadays, data transfer is among the most significant task to be accomplished by a data developer. There are numerous data transfer methods available in the market, but they are not reliable and safe. These reliability and security issues have caused lots of problems to those who need the data in its original form. However, you’ve fiber optic cables now.

Fiber optic cables are the most dependable and elegant approach to transfer data in the field. They set a standard, which may be hardly reached by other cables. It can possess a signal with highest efficiency, since the signal in a very fiber optic cable isn’t getting that much attenuated, at a least signal loss.

Furthermore, unlike copper wires, fiber optic cables don’t let intrusion of outdoor signals. In order to mix or access the signal carried from the fiber optics, one must intervene physically, which cannot go undetected without correct surveillance equipment. Therefore, fiber optic cabling is several folds securer compared to the regular copper cables. Also, since fiber optics isn’t made of copper wire or any other metallic wires, it’s much less denser, thus which makes it convenient to carry around and also needs fewer personnel for installing. Nevertheless, the cost of fiber optic cable might be a little higher than the regular cables, but studying the advantages and sum of money trapped in its maintenance and functioning accocunts for much more than the fee incurred.

With proper installation of fiber optic cables, the info could be delivered to more than a 1000 kilometers distance however, if the cables aren’t installed since they ought to be, then the data may well not even visit a person sitting beside the sender. For the effective usage of fiber optic cables, the installer should become aware of the policies information required.

Now the fundamental question that arises is the fact that the thing that makes the use of fiber optics installer effective? The answer is the data concerning the types of fiber optics and their installation this includes the techniques of protecting these cables in numerous environmental conditions. Fiber optic cables are designed to be able to minimizing the worries caused to the cable i.e., temporary or long-term stress and in addition to that, there should be fire safety compliance with in the cable. All these efforts assembled to style a fiber optic cable are effective only if the cable is installed properly by using the fiber optics installer guide.

There are lots of fiber optic cables which are manufactured as reported by the dependence on their usages which categorizes them into 2 types which can be maximum tensile strength and minimum bend radius. These optical cables which can be manufactured for special purposes as well as need special type of skills and their installation needs to be followed as per the manufacturers’ specifications for their proper and effective working. Moreover, from your manufacturing types, the fiber optic cables can be categorized into indoor fiber optic cables and outdoor fiber optic cables. These two differ from their manufacturing aspects and different features will also be added to them. The fiber optic cables useful for the great outdoors possess a rugged outer body and less flexibility in order to withstand the outdoor harsh temperature and environment whereas the indoor fiber optic cables have a flexible and fewer rugged cover. These two cables need different kinds of fiber optics installer guidance to put in.

Technology is incredibly dependent on its sources and fiber optic cables are among the most dependable sources. Nevertheless the users must remember the different types of cables, the manufacturing, cellular phone and structure which may be done using a fiber optics installer guide.

Fiber optics installer guidance is indeed important, where can users get the right suitable guidance for installation? Generally, fiber optics installer guidance could be a paper manual with all the fiber optic cable installation tools. However, installing different type of cable comes to a different guidance, such as installing Cat 7 cable is different from that of MPO to LC cable.