Singlemode vs Multimode Fiber Optic Cable

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

Fiber optic cables are being widely used in telecommunication and data networks around the world. Small networks like branch offices and large corporate offices having multiple campuses are making use of the fiber optic technologies to provide their users a reliable and efficient network.
Fiber optic cables use light as the medium to transfer the data signals from one end to the other end. Unlike the copper or coaxial cables, there is no electric pulse or current involved in the transmission of signal through a fiber optic cable. Fiber optic cables are available in two main categories, i.e. single-mode fiber and multimode fiber. This article will look into the details of the two types of fiber optic cables and portray the differences, benefits and use cases for both types of fiber.
Single-mode Fiber Optic Cable
Single-mode fiber optic cables are designed in such a way that it allows light to travel straight down the fiber core with least amount of diffraction and reflection. The light travels from source to the destination in a straight line. The core of the single-mode fiber optic cable is very thin, usually in the range of 8.0 – 10.5 micrometers. Single-mode fibers, due to their thin core and less reflection characteristics, are able to carry the signals over longer distances and achieve very high data transfer rates as compared to the multimode fiber optic cables.
The above-mentioned characteristics are beneficial for transmission networks that cover a very large geographical area, however, the increased efficiency is required in the transceivers of the single-mode fiber optic cables. Usually, a very precise and high intensity laser beam is used as a source of light in single-mode fiber optic transceivers. This results in higher costs of the transceivers. On the other hand, the thin core proves to be economical as far as the cost of the fiber optic cable is concerned.
From the above-mentioned arguments, it can be inferred that the single-mode fiber is useful for those networks where there is a requirement for high bandwidths (typically in the range of 10 Gbps – 100 Gbps), and longer distance links. The cost of installing a single-mode fiber optic network is justified in those cases.
Multimode Fiber Optic Cable
Multimode fiber optic cables are constructed in such a way that it allows light to travel through different paths inside the core of the fiber optic cable. The reason behind this is that the core of multimode fiber optic cable is thicker than that of the single-mode fiber optic cable. The core of multimode fiber optic cable is in the range of 50 – 100 micrometers. This thicker core allows the light to reflect and refract inside the core of the fiber optic cable and create multiple “modes” of the light.
The larger core of the multimode fiber optic cable also allows the use of light emitting diodes (LEDs) to be used as the light source for its transmission. This results in to the lower cost of allied electronics and transceivers for the multimode fiber optic cable.
The limitation for multimode fiber optic is the distance and bandwidths. Due to the less precise electronics and losses due to reflection and refraction, the multimode fiber optic cable is unable to carry the data over longer distance links and is also not capable to provide higher bandwidths. Several types of multimode fiber optic cables are available such as OM1, OM2, OM3 and OM4. The widely used 10 Gbps bandwidth is supported by OM4 fiber optic cable up to a distance of 400 meters only.
In the light of above facts, it can be concluded that the single-mode and multimode fiber optic cables are equally useful and beneficial if deployed in their relevant use cases. Single-mode fiber optic cable is beneficial for larger networks and multimode fiber optic cable is useful in smaller office networks where the maximum link distance is not a limiting factor. Multimode fiber optic networks are economical and present an excellent use case for such type of networks.

Very Effective Method of Fiber Optic Cables Selection

After the distribution network plan is developed, the next step we have to do is the selection of the right fiber optic cable. Remember the bulk of the Fiber Optic Cable installed today is for either telephone or office applications. Industrial sites bring some challenges that are not address by many of the common fiber optic cable installation design. Just due to the local telephone company would rather a particular type of fiber optic cable does not mean it is the right one for a facility.

After the distribution network plan is developed, the next step we have to do is the selection of the right fiber optic cable. Remember the bulk of the Fiber Optic Cable installed today is for either telephone or office applications. Industrial sites bring some challenges that are not address by many of the common fiber optic cable installation design. Just due to the local telephone company would rather a particular type of fiber optic cable does not mean it is the right one for a facility.

The common rule of thumb for selection optical cable in industrial setting is to use 62.5/125 μm or 50/125 μm Multi-mode fiber cable. The cable should be rated for both indoor and outdoor use and must have an FT-4 flame rating if it is used for indoors. Aluminum interlock armor is preferred over steel tape for all but long, buried runs. Fiber counts should be a minimum of 12, with 24 fibers as the standard for main backbones. More specific selection details depend on the area where the cable will be installed.

Indoor Office Installation

Fiber selection for office applications is relatively simple. The fiber must be flame-rated for either FT-4 general use or FT-6 for plenum. Typically, tight-buffered cable with Kevlar strength members and a light jacket is used. There is little reason to use loose tube as it is more difficult to install and usually does not meet the flame rating standards. As well, fiber optic cables in these environments do not require armor as the chance of crush or pull damage is relatively low. Because jacketed fiber optic cable is more rugged than most coaxial and twisted-pair cables, plan to armor fiber only in the places where coaxial cables would be Armored Fiber Cable.

Indoor Industrial Installations

If fiber optic cable is being installed in plant-floor conditions. It is possible to be installed in existing cable trays and be subjects to more stresses than office cable systems. Thus, some form of armor is recommended, usually aluminum interlocked (TEC style) armor. This armor must be electrically bonded to ground at all distribution cabinets.

Inter-building Installation

Industrial sites often need a combination of indoor and outdoor fiber routing. Telecommunication industry guidelines recommended switching between indoor and outdoor fiber cable types at each transition, a solution than is not practical for most industrial sites. On a typical site, this would require numerous patch boxes or splices and is not worked for both cost and attenuation(signal loss) reasons. Instead, FT-4 flame-rated, tight-buffered cable should be used so that the cable can transmit both indoor and outdoor environment.

Long-Run Outdoor Installations

Outdoor fiber cable generally falls into three categories, direct burial, underground conduit, and aerial. These cables are manufactured specifically for outdoor applications and are recommended for any long outdoor cable runs, especially in region subject to cold weather. Most are loose tube designs with high tensile strength, to withstand environmental conditions, and gel filling, to prevent water migration. The jacket materials are specially selected to be abrasion and ultraviolet resistant. If a facility is planning to install long outdoor runs it will need to work closely with the manufacturer ti determine the right cable for its application.

Indoor and Outdoor fiber optic cable delivers outstanding audio, video, telephony and data signal performance for educational, corporate and government campus applications. With a low bending radius and lightweight feature, this cable is suitable for both indoor and outdoor installations. Typical indoor and outdoor cables are loose tube and tight buffer designs, and we also supply ribbon cables, drop cables, distribution cables and breakout cables. These are available in a variety of configurations and jacket types to cover riser and plenum requirements for indoor cables and the ability to be run in duct, direct buried, or aerial/lashed in the outside plant. In addition, Fiber-Mart can supply Indoor and Outdoor fiber optic cable. If you have any questions or requirement of Indoor and Outdoor fiber optic cable,welcome to contact us: product@fiber-mart.com.

How To Choose The Right Fiber Patch Cable ?

There are many different types of fiber optic cable. Fiber-Mart stocks hundreds of varieties and we can custom build thousands of other types. The sheer number of options can be overwhelming to people that don’t work with fiber optic cable regularly. So here are some common questions. 

There are many different types of fiber optic cable. Fiber-Mart stocks hundreds of varieties and we can custom build thousands of other types. The sheer number of options can be overwhelming to people that don’t work with fiber optic cable regularly. So here are some common questions.

Do you need singlemode or multimode fiber optic cable?

If you already have a cable and you need more of it, you can usually tell the type of cable by the color of it. Single-mode cable is typically yellow.  Multi-mode cable (either 62.5 micron or 50 micron) is usually orange. And 10GB multi-mode cable is usually aqua.If you don’t know the color, you have to find some sort of documentation that describes the type of cable you need. Below are some terms and the type of cable they are usually associated with.

·OS1, OS2, 9 micron, 9µm, 9/125 = Singlemode

·OM1, 62.5 micron, 62.5µm, 62.5/125 = Multi-mode 62.5

·OM2, 50 micron, 50µ, 50/125 = Multi-mode 50

·OM3, 10GB, 10gig, 50 micron, 50µm, 50/125 = 10GB Multi-mode

As you can see, it can be a bit confusing since both 50 micron and 62.5 micron are multi-mode and are orange. It’s also confusing because 50 micron cable can also be 10GB aqua cable. In cases where it isn’t clear, you may have to find documentation for the hardware you are using to figure out what you really need.The different cables all have strengths and weaknesses.  Single-mode cable is frequently used for very long distance cable runs. It’s not unusual to use a 20KM piece of single-mode cable. But, the hardware to support single-mode cable is traditionally more expensive.

Multi-mode fiber doesn’t work over such long distances, but the hardware for it is traditionally less expensive. Multi-mode 62.5 and multi-mode 50 are commonly used with LED based communications hardware. 10GB multi-mode, which is also 50 micron, is faster than the other types of multi-mode, mainly because its been designed to work with faster, laser based communications hardware.

What is Return Loss?

When light hits the end of a fiber optic cable, a portion of it can bounce back towards the source. This is known as Back Reflection and it can cause a few different problems. Return Loss is the term for how much the end of a cable cuts down on Back Reflection. You want as much Return Loss as possible.

What is Insertion Loss?

When light travels out of the port on your hardware into the fiber optic cable, some of it is lost in the transition. The amount that is lost is referred to as Insertion Loss. You want as little Insertion Loss as possible

Do you need UPC?

Most of our customers are simply looking to minimize Insertion Loss and maximize Return Loss. This means they want as much light as possible to pass through the fiber to its destination and as little light as possible to bounce back to its source. For most applications, UPC will provide this for you. However, in some circumstances, you need more Return Loss than UPC can offer. That is when you use APC. If you have green connectors on your fiber or devices, you may need APC.

Do you need APC?

APC is designed specifically to maximize return loss. APC ends are actually polished to have an ~8° angle on the end of the fiber. An APC end will almost always have a green connector to make it clear that the fiber is APC. The part that is actually polished to an angle is so small that you won’t be able to tell it is angled from looking at it.

If you mix APC and UPC, the result can be tremendous insertion loss (meaning a lot of light will be lost at the point where you connect the APC to the UPC). So, if you have a port on your device that specifies it needs APC, you will need to use a cable with an APC end on it. If you have a cable with a green connector and you want to attach an adapter cable to the end, you will need to make sure an APC end connects to it.

Do you need simplex, duplex, or more?

Simplex cable has a single fiber optic cable and usually one connector on each end. Fiber optic communication equipment typically sends data in one direction on a cable. So, for bi-directional communication, hardware typically uses duplex cable.

Duplex cable has two fiber optic cables and it usually has two connectors on each end. LC and SC connectors can be joined together with a clip that spaces them the correct distance apart to plug both connectors into equipment at the same time. If there is equipment that requires the ends be plugged in closer or farther apart, you can simply remove the clips.

You can also get cable that has many more strands of fiber in it.

What jacket do you need?

Our duplex cable typically comes in a basic zip-cord style where the two fibers are in their own jackets and those two jackets are seamed together. You can also get round jacket cable where multiple cables are run inside a single round jacket, often with reinforcers running through it.

If you are going to be running the cable outdoors or in a conduit where it may be exposed to moisture you will need an Outdoor rated cable.

If the cable is going to be abused in any way, including running along the ground where it might be stepped on or used in a way where it’ll be unwound and wound back up repeatedly, armored cable may be required.

If you want a cable that can be run over by a tank, just mention it, we have something that can handle tanks.

If the cable is in a plenum space, you may need a cable that is plenum rated. Plenum is an air space above multiple rooms. For instance, in office buildings, it’s not unusual for the walls of rooms to only go up as high as the drop ceiling. If you pop your head above the ceiling, you’ll see across many walls and see the ceilings of many rooms. That area is a plenum area where multiple rooms share a common overhead air space. The rules for using plenum vary based on local building codes.

How much do you need?

This is a pretty simple question, but if you need a cable fast, it can be very helpful to know the effect that length has on fiber optic cable.  10GB Multi-mode cable will do up to 10GB/s up to 330M. But, if you need a 20M 50 micron cable that can do 10GB/s then you can often use Multi-mode 50 cable available instead. Here’s a quick chart to show bandwidth vs speed:

Fiber optic patch cord is available in OM1, OM2, OM3, OM4 multimode and OS2 single-mode types. Both ends of the cable are terminated with a high performance hybrid or single type connector comprising of a SC, ST, FC, LC, MTRJ, E2000 connector in simplex and duplex. These are typically not ruggedized, depending on the application, making them suitable for internal use. How to choose right patch cables for your network?

Just follow these 6 steps:

Step 1: Choose the Right Connector Type (LC/SC/ST/FC/MPO/MTP)

On both ends of the fiber optic patch cord are terminated with a fiber optic connector (LC/SC/ST/FC/MPO/MTP). Different connector is used to plug into different device. If ports in the both ends devices are the same, we can use such as LC-LC/SC-SC/MPO-MPO patch cables. If you want to connect different ports type devices, LC-SC/LC-ST/LC-FC patch cables may suit you.

Step 2: Choose Single-mode or Multimode Cable Type?

Single-mode fiber patch cord uses 9/125um glass fiber, Multimode fiber patch cord uses 50/125um or 62.5/125um glass fiber. Single-mode fiber optic patch cord is used in long distance data transmission. multimode fiber optic patch cord is use in short distance transmission. Typical single-mode fiber optic patch cord used yellow fiber cable and multi mode fiber optic patch cord used orange or aqua fiber cable.

Step 3: Choose Simplex or Duplex Cable Type?

Simplex means this fiber patch cable is with one cord, at each end is only one fiber connector, which is used for Bidirectional (BIDI) fiber optic transceivers. Duplex can be regarded as two fiber patch cable put side by side, which is used for common transceivers.

Step 4: Choose the Right Cable Length (1m/5m/10m/20m/30m/50m)

Fiber optic patch cables are made in different lengths, usually from 0.5m to 50m. You should choose an appropriate cable length according to the distance between the devices you want to connect.

Step 5: Choose the Right Connector Polish Type (UPC/APC)

Since the loss of the APC connector is lower than UPC connectors, usually, the optical performance of APC connectors is better than UPC connectors. In the current market, the APC connectors are widely used in applications such as FTTx, passive optical network (PON) and wavelength-division multiplexing (WDM) that are more sensitive to return loss. But APC connector is usually expensive than UPC connector, so you should weigh the pros and cons. With those applications that call for high precision optical fiber signaling, APC should be the first consideration, but less sensitive digital systems will perform equally well using UPC. Usually, connector color of APC patch cable is green, and of UPC patch cable is blue.

Step6: Choose the Right Cable Jacket Type (PVC/LSZH/OFNP/Armored)

Usually, there are three cable jacket types: Polyvinyl Chloride (PVC), Low Smoke Zero Halogen (LSZH) and Optical Fiber Nonconductive Plenum (OFNP). You can see there features in figure below and choose the right one for your network.

Besides the three cables mentioned above, there is another common cable—Armored Cable. The double tubing and steel sleeve construction make these patch cables completely light tight, even when bent. These cables can withstand high crushing pressures, making them suitable for running along floors and other areas where they may be stepped on. The tubing also provides excellent cutting resistance, abrasion resistance, and high tensile strength. Fiber-Mart provides all kinds of fiber optic patch cables to meet demands of various customers!Any questions feel free contact us: product@fiber-mart.com