Is your company entering the fiber optic cable assembly business, and you&#;re &#;setting up shop&#;? In your research, you may be discovering that most equipment is not offered as a one-size-fits-all, universal solution.

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In fact, a key piece of fiber optic test equipment &#; the passive component tester (PCT) &#; must be correctly configured by the seller to support your product requirements.

When I talk with companies entering this business and researching PCTs, I ask a lot of questions about the cable assembly or patch cord/jumper they intend to fabricate. Why? Having a clear understanding of the product helps us clarify your test equipment requirements &#; and ensures you get an accurate quote. But here&#;s the issue: You may be in embryonic stages of &#;setting up shop&#; and may not have all the answers. So where do you start?

Start here: Answer these 7 foundational questions. This will help prepare you to order a PCT with the right test set configuration for your fiber optic product.

Passive component testers are a combination of firmware and hardware that, as noted earlier, must be correctly configured for your specific product. Many PCTs offer the following features:

• Insertion Loss/Return Loss module, which contains light sources and a detector
• A switch module, from 4 to 48 (or more) channels
• A chassis to fit the above modules, either 3 or 8 slots

While the above features may appear straightforward, every test equipment seller worth his salt will ask a surprising number of questions regarding the product you plan to test. To get started, here are 7 basic questions you should be prepared to answer. Your answers will guide you to select a PCT with the correct test set configuration &#; one that is the most economical solution for your requirements.

Question 1: What type of fiber will you test: single-mode, multimode, or both?

While this seems like an obvious question, some people assume a passive component tester can test both single-mode and multimode fibers. However, different modules are required to test single-mode and multimode. Keep in mind, that no testing module is universal.

Question 2: What type of connectors do you have?

You&#;ll need to clarify the connector type for each fiber optic cable assembly to be tested to get the right launch cables and detector adapter. (Often, cable assemblies do not have the same connector on both ends.) For example, if your patch cord includes any of the following connector types on both ends, then you can measure either individual Insertion Loss or total link loss using the Viavi MAP-300 8-Slot Mainframe, MAP-300 3-Slot Mainframe or MAP-300 3-Slot Mainframe with Touchscreen.

• FC or FC/APC
• SC or FC/APC
• ST
• LC or LC/APC
• MTP (MPO) male one end, female the other
• In essence, any cable that can be looped back and connected end to end

Question 3: How many channels will you need?

Recently I visited a fiber optic cable assembly manufacturer in Mexico. This company is fabricating large, 144-fiber cable assemblies. It would be prohibitively expensive for them to use a passive component tester with 144 channels in order to test all fibers at the same time. Instead, they use a 24-channel switch and test in batches of 24 fibers. In this instance, the manufacturer does not need to measure all connectors at once. How many fibers will you need to measure simultaneously? When researching passive component testers, be sure to ask how many channels each device has.

Question 4: Is the ability to test Return Loss (RL) required?

Do your customer specifications require you to measure Return Loss? If so, the passive component tester you select must offer this capability. Many end customers require Return Loss to be tested. This is based on the idea that good and consistent RL values imply that the manufacturing process is precise and stable.

Question 5: Will you measure Insertion Loss (IL) individually per end &#; or measure total Insertion Loss?

Let&#;s say you&#;re fabricating a patch cord with a connector on both ends. Generally, the cable has zero loss over its short length. That means all the loss is associated with the connectors &#; the way they&#;re assembled, polished, and so forth. If you connect a patch cord into a circuit that&#;s already been referenced and you connect both ends of the patch cord, you will get the total loss for the patch cord. When both ends of the patch cord are connected, test equipment cannot discriminate which end the loss is coming from.

To measure individual Insertion Loss, you&#;ll need to purchase a PCT offering this capability. Measuring individual IL is beneficial because this can help to ensure your fiber optic cable assembly process is stable and consistent.

If the Insertion Loss at one end of the cable is high and the other end is low, this tells you there&#;s some variation in the process, and you&#;d want to look into that.

Question 6: Which measurement wavelengths do you require?

For the most part, corporate and government communication entities connecting data centers around the world &#; bringing fiber to the office (FTTO) and fiber to the home (FTTH) &#; have standardized measurement wavelengths. When researching passive component testers, clarify whether they support these wavelengths:

• Multimode: 850mm and mm
• Standard module for single-mode: mm and mm
• The full wavelength version for single-mode adds: mm and mm for complete FTTX coverage

Question 7. What does the future hold?

I see a growing trend with manufacturers entering the fiber optic cable assembly market. Typically, their initial products are fairly simple. Soon, though, they make the jump from highly competitive, &#;commodity&#; products to more complex products with higher added value &#; and larger profit margins.

As you enter this market, you may only need relatively simple, entry-level test equipment. Based on my experience of working with a lot of companies entering the fiber optic market, it&#;s highly likely that you will expand to more complex products. These new products will require different test set configurations for your passive component tester. At this stage in your purchase process, take time to think about future product expansion. If possible, buy for the present &#; and for the future.

Concluding thoughts&#;

As you&#;re researching passive component testers to &#;set up shop,&#; I&#;m happy to offer guidance in your selection process. It&#;s critical that you purchase the RIGHT fiber optic test equipment. Your decision-making process should result in a PCT with the correct test set configuration that meets your current product requirements and, ideally, supports future expansion.

 

Additional resources from the FOC team include:

About the Author

Chris Rollinson

Chris Rollinson, Business Development, Test, Technical Sales Chris began his career at Fiber Optic Center in with 40 years of experience in test and measurement. Chris handles Business Development for Test and Measurement with a specialty area in the MAP passive component tester. Chris has nearly 20 years in fiber optics, mostly as application engineer and later product line manager in instrumentation at JDSU, where, in the fiber boom, he designed and installed several complex optical measurement systems. Further back he was involved with shock , vibration and sound measurements with the Danish company Bruel & Kjaer. Chris Graduated from the University of Leeds (UK) with a BSc. in Physics. He Lives in Ottawa, Canada with his Wife, Dog, several old cars and a motorcycle.

Fiber Optic Cable Buying Guide

Choosing single-mode or multimode fiber for high-performance data networking and telecommunications

Fast data transmission, thinner, lighter cables and long signal range are just a few of the benefits that make fiber optic cable a solid choice for corporate data networking and telecommunications.

This buying guide will help you:

• Understand what fiber optic cable is and recognize key features
• Learn the important questions to ask before selecting fiber optic cable
• Find the right type of fiber optic cable for your network
• Compare the different types of optical fiber cable available

How to Choose Fiber Optic Cable

Fiber optic cable selection can be complex due to the variety of cable types, performance characteristics and more precise installation requirements. Start by determining requirements for the following:

• Distance
• Network Speed
• Cable Jacket
• Connectors

Once you have narrowed down your choices, you should also consider cost and future-proofing. Additional requirements will be driven by the needs of your specific application. If you need assistance in determining requirements or selecting pre-terminated or custom fiber cable, please contact us.

Network Speed and Distance
Multimode fiber (MMF) used to be the automatic choice for datacenters and corporate networks because it was less expensive than singlemode fiber (SMF). Nowadays, the cost difference is not so significant. For example, the price of a 3 meter LC-to-LC duplex SMF cable is about one US dollar more than the equivalent MMF cable.

Instead of focusing on singlemode vs. multimode, focus on the connection distance and network speed dictated by the overall network design. If you need to move a large amount of data over a relatively short distance (for example, less than 300 meters), OM3 MMF might be the best choice. If data transmission speed or distance are key requirements, consider SMF. Note that MMF range depends on the OM rating of the cable.

Refer to Table 2: Fiber Optic Cable Speeds and Lengths for guidance.

Cable Jacket
All indoor fiber cabling must meet local fire codes. In the US, fire rating and jacket identification is defined by Article 77 of the National Electric Code (NEC). If your cable will run through risers or plenum spaces, make sure the cable jacket is rated accordingly.

In addition to fire rating, other cable jacket properties such as flexibility and strength under tensile load should be considered. For more information on jacket materials and fire ratings, see Fiber Optic Cable Jackets.

Connectors
Fiber optic cable terminations are typically dictated by the ports on your network equipment. For example, if your 10G Ethernet switch has multi-fiber MTP ports, you'll need cables with the required number of fibers.

If you are selecting cable for a 40GbE or 100GbE application, consider Active Optical Cables (AOCs). They combine an optical fiber cable and transceivers, eliminating the connector entirely.

Application Starting Points

Key Requirement Fiber Solution Product Options 10G Server Rack OM3 or OM4 cable OM3
OM4 40G Switch to Switch MTP, AOC MTP/LC
AOC 40G Switch to 10G Servers MTP-to-LC fan-out cables
Break-out cassettes MTP/LC Fan-Out High Port Density Connectors with Push/Pull Tabs Push/Pull Tabs 200/400G Switch to Switch OM4 with CS connector OM4/CS

I need a custom cable. What are the next steps?
Eaton offers custom solutions to simplify installs and save money. Specify the fiber cable solution you need using our quick and easy order form.

Ask Eaton:

Optimizing Optical Fiber Networks

Fiber Optic Cable Basics

What is a Fiber Optic Cable?
A fiber optic cable is a type of cable that uses light to transmit data over long distances. It consists of a core made of glass or plastic that is surrounded by layers of protective material, such as cladding. The core of the cable is where the data is transmitted as light signals, and the cladding helps to keep the light signals confined within the core. A coating and strength member protect the delicate fiber optic core from damage.

Fiber optic cables are used in a variety of applications, including telecommunications, internet service, and cable television. They offer several advantages over traditional copper cables, including faster data transmission speeds, immunity to electromagnetic interference (EMI), and the ability to transmit data over much longer distances. They are also more durable and less susceptible to damage than copper cables.

Fiber optic cables are available in various types, including single-mode and multimode fiber, and they can be used in various types of network configurations, including point-to-point, ring, and star. They are typically used for high-speed data transmission and are becoming increasingly important as demand for faster and more reliable wide area network connections continues to grow.

Core - At the center of a fiber optic cable is a thin glass tube called a core that transports light pulses generated by a laser or light emitting diode (LED). Singlemode cores are typically 8.3 or 9µm, while multimode cores are available in 50 and 62.5µm diameters.

Cladding - A thin layer of glass that protects and surrounds the fiber core, reflecting light back into the core causing light waves to travel the length of the fiber.

Primary Coating - This layer of thicker plastic is also known as the primary buffer. It is designed to absorb shocks, prevent excessive bending and reinforce the fiber core.

Strength Member or Strengthening Fibers - From gel-filled sleeves to strands of Kevlar, the strength member is engineered to protect the fiber core from excessive pull forces and crushing, particularly during installation.

Outer Jacket - The outer jacket, or cable jacket, provides a final layer of protection for the core conductor and further strengthens the cable. The jacket is color coded to identify the type of optical fiber in the cable: yellow for single mode, orange for multimode, and so on. Cable jackets also have fire ratings, such as OFNR, OFNP or LSZH.

How Fiber Optic Cable Works

Light pulses travel down the core of the fiber optic cable by reflecting off of the sides. With the exception of the light source, no power is required to transmit a signal. Light pulses will travel for many miles before they weaken and need to be regenerated.

Core size is important in determining how far a signal will travel. In general, the smaller the core, the farther the light will go before it needs regenerated. Single Mode Fiber (SMF) has a small core, which keeps the path of light narrow and allows it to travel up to 100km. Multimode Fiber (MMF) has a bigger core capable of carrying more data but it is susceptible to signal quality problems over longer distances, making it more suited to premises cabling and short haul networks.

How far can a fiber optic cable carry a signal?
Signal transmission distance is dependent on the type of cable, the wavelength and the network itself. Typical ranges are about 984 ft. for 10 Gbps multimode cable and up to 25 miles for singlemode cable. If a longer span is required, optical amplifiers or repeaters can be used to regenerate and error correct the optical signal.

Can the light generated by a singlemode laser damage your eyes?
Yes, the laser light from the end of a singlemode cable or the transmit port on a switch can seriously damage your eyes. Always keep protective covers over the ends of fiber cables and ports.

Advantages of Fiber Optic Cable vs. Copper Cable

Faster data transmission speeds - Photons traveling at the speed of light reach speeds over a hundred times faster than electrons traveling over a copper conductor. In comparing the data transmission speed of fiber and copper, fiber wins easily. Copper currently maxes out at 40 Gbps, whereas OM5 fiber reaches speeds of 100 Gbps.

Higher bandwidth - Fiber optic cables have a much higher bandwidth capacity than copper cables, allowing for more data to be transmitted at once.

Longer transmission distances - Over long distances, copper and fiber cables both experience signal loss, but this attenuation is much greater with copper. Over 100 meters, it is estimated that fiber loses only 3% of its signal strength, whereas copper loses 94% over the same distance.

Immunity to electromagnetic interference (EMI) - Copper wires produce a field of electromagnetic interference, which can cause signaling errors in other cables. Fiber optic cables do not conduct electricity and are not susceptible to EMI.

Electrical Isolation - Because fiber optic cables do not carry electricity, there is no need to ground the transmitter and receiver. Nor is there any danger of electrical shock, arcing, heat or fire.

Lighter, Thinner Cable - Fiber cables are about a quarter the diameter and a tenth the weight of copper cables, making them easier to install and promoting better air flow in rack enclosures.

Better reliability - Fiber optic cables are more durable and less susceptible to damage than copper cables, making them more reliable for high-speed data transmission.

Security - Fiber optic cables are more secure than copper cables because it is difficult for unauthorized users to tap into the data transmission.

Environmentally friendly - Fiber optic cables are made of glass or plastic, which are environmentally friendly materials, whereas copper cables are made of copper, which is a finite resource.

What's the difference between fiber optic and Ethernet cable?
Ethernet cable has become synonymous with copper category cable but Ethernet is actually the networking protocol that allows devices to communicate over copper or fiber cable. Depending on requirements, network designers may choose to use either fiber or copper cable, and may use both in different parts of the network. Fiber is typically used to connect two high-speed devices (e.g. switch to switch) in data centers and campus networks where bandwidth and distance may be critical factors. In some cases, a network designer may be able to save money by using copper cable with similar performance in place of fiber optic cable. For example, less expensive 10G-certified Cat6a cables can be used in place of duplex fiber cables, which also require costly transceivers.

In residential applications, most telecommunications carriers have adopted some form of Fiber to the X (FTTX), a general term that encompasses configurations such as Fiber to the Premises (FTTP) and Fiber to the Home (FTTH). The last cable run will be defined by the equipment installed by the carrier in the home or business. If the output port is copper, then a standard copper Ethernet patch cable can be used. If the output port is fiber, then a fiber Ethernet cable is needed between the switch or router and the computer. The computer would need a fiber port or a media converter to transition from fiber to copper in order to complete the connection.

What is the defference between fiber internet and cable (copper) internet?
Fiber and cable internet both offer high-speed internet access, but there are some differences between them:

Speed: Fiber-optic internet has a faster maximum speed than cable internet. Fiber-optic internet can reach speeds up to 10 Gbps, while cable internet typically offers speeds up to 1 Gbps.

Reliability: Fiber-optic internet is known to be more reliable than cable internet as it is not affected by weather or physical interference, while cable internet can be affected by such issues.

Latency: Fiber-optic internet typically has lower latency than cable internet, meaning that data takes less time to travel from the source to its destination.

Availability: Cable internet is widely available, especially in urban areas, but fiber-optic internet is not yet as common and may not be available in all areas.

Often times, the choice between fiber and cable internet depends on what's available in your area.

Fiber Optic Cable Types

Singlemode vs. Multimode
Fiber optic cable is available in two "modes": multimode or singlemode. Mode refers to pulses of light: multiple pulses or a single pulse.

Wirenet Product Page

Multimode fiber (MMF) cable is a type of fiber optic cable that is designed to allow multiple modes or pulses of light to propagate through the core of the cable. The relatively wide core allows it to carry multiple streams of data simultaneously at wavelengths of 850nm or nm.

Due to high dispersion and attenuation rates, multimode fiber is commonly used in shorter distance data transmission applications, such as in office buildings, schools, and hospitals. The larger core size allows for the use of less expensive light sources, such as a light emitting diode (LED) or Vertical Cavity Surface Emitting Laser (VCSEL), which can be used to transmit data over distances of up to several hundred meters.

Multimode fiber is less expensive than singlemode fiber and is easier to install and maintain, but it has several disadvantages compared to singlemode fiber, including slower data transmission speeds, shorter transmission distances, and lower bandwidth capacity. It is also more susceptible to signal degradation and attenuation over longer distances.

Singlemode fiber (SMF) cable is a type of fiber optic cable that is designed to transmit light through the core of the cable. Compared to multimode fiber, singlemode fiber has a small diameter core, typically around 9 microns. This smaller core size allows the light signals to travel much further without spreading out, enabling singlemode fiber to transmit data over distances of up to several kilometers. It uses a laser diode as its light source and a bandwidth in the and nm range.

Singlemode fiber is commonly used in high-speed data transmission applications, such as in telecommunications, internet service, and cable television. It is also used in high-bandwidth applications, such as data centers and medical imaging, where high-speed and long-distance transmission is required.

Singlemode fiber is more expensive than multimode fiber and requires specialized equipment for installation and maintenance, but it offers several advantages, including faster data transmission speeds, longer transmission distances, and higher bandwidth capacity.

Why is multimode fiber optic cable is designated 50/125 or 62.5/125?
These designations refer to the diameter of the core and cladding. For example, a 50/125 cable has a 50 micron core and a 125 micron cladding.

Simplex vs. Duplex
Simplex cable uses a single strand of fiber with a transmitter (TX) on one end and a receiver (RX) on the other. The cable is not reversible and supports only one-way transmission. It is typically used in monitoring applications where a sensor sends time-sensitive data back to a centralized system.

Full duplex cable uses two fibers to simultaneously transmit and receive data, essentially two simplex cables that work together to handle bidirectional data transfer. The twin connectors on either end are capable of transmitting and receiving simultaneously. Half duplex cables are also capable of two-way communication but not at the same time. Duplex cables are typically used to connect network devices in a high-speed network, such as switches, servers and storage systems.

Fiber Polarity

In duplex fiber cables, it takes two fibers to make a bidirectional connection: one to transmit and one to receive. Polarity refers to the direction in which light travels from one end of the optical fiber to the other. To make a connection, a transmitter (Tx) must be connected to a corresponding receiver (Rx) on the other end of the cable.

Polarity errors in installation are common enough that TIA issued guidelines to help installers maintain polarity, particularly across multiple segments (see ANSI/TIA-598-C, Annex B). The standard defines position A and position B labeling for connectors and adapters, with position A on one end being routed to position B on the other end. When looking at a connector straight on with keys in the "up" position, "A" is always on the left and "B" is always on the right.

Eaton fiber patch cords are also color-coded. Notice how the yellow sleeve on the cable above indicates Position A on one end and Position B on the other.

Switchable Polarity Connectors

Why Are Switchable Polarity Connectors Necessary?
A-B duplex patch cords provide a crossover, with transmitter connecting to receiver. Regardless of whether the connection is a single cable or a series of patch cords, adapters and patch panels, when you add up all the crossovers in a channel it should be an odd number.

Most fiber optic duplex cables have fixed polarity, meaning the positions of the LC connectors cannot be changed. However, sometimes switchable polarity cables are necessary, either by design or to fix installation errors. Fiber between buildings or between patch panels is often run straight through (i.e. not crossed), even though this is contrary to the ANSI/TIA standard recommendations. Uncrossing patch cables is also a common fix for polarity errors in installation.

How to Switch a Connector's Polarity
The LC connectors on switchable polarity cables are held in place by a clip. Releasing the clip allows the A and B positions to be swapped, converting an A-B cable to an A-A cable.

Types of Switchable Polarity Fiber Optic Cable

Miscellaneous Fiber Cable Types

Duplex Zipcord Fiber
Zipcord is a type of electrical cable with two or more connectors that can be separated by pulling them apart.

Duplex zipcord fiber consists of two fibers surrounded by strength members and an outer jacket. The example on the right is a duplex multimode zipcord cable with twin LC connectors on either end.

Mode Conditioning Cables
A Mode Conditioning patch cord (MCP) is a duplex cable with multimode to multimode on the receive (Rx) side and singlemode to multimode on the transmit (Tx) side.

By allowing a singlemode signal to be converted and transmitted over multimode fiber, Mode Conditioning cables avoid the expense of an expensive network upgrade to replace legacy Gigabit LX transceivers.

Can I mix singlemode and multimode fiber and equipment on the same network?
No. Singlemode fiber (SMF) and multimode fiber (MMF) have different core sizes so mixing cable types causes differential mode delay (DMD), resulting in errors at the receiver. Mode Conditioning patch cables avoid DMD by launching the singlemode signal at an offset to the center of the MMF core. This "mode conditioning" creates a signal that is similar to typical multimode launch.

Active Optical Cables (AOCs)
Active Optical Cables (AOCs) are fiber optic cables with transceivers permanently bonded to each end, eliminating the need for connectors. AOCs are typically used in top-of-rack applications where link distances are short. The thin cables help to maintain air flow when port density is high.

Multi-Strand Fiber Cables
Multi-strand fiber is similar to duplex fiber. It has multiple strands of fiber carrying data in one direction and a similar number of strands supporting data transfer in the opposite direction. Multi-strand fiber is designed to support data rates above 25G and uses an MPO/MTP connector.

Cables typically have 12 or 24 fiber strands (referred to as 12F or 24F) in a single jacket. Multi-strand fiber can also be made as a breakout cable with an MPO/MTP connector on one end and multiple duplex LC connectors on the other end.

Loopback Cables
A loopback cable, also known as loopback tester or loopback adapter, is used to test signal transmission and diagnose problems. It plugs into an Ethernet or serial port and routes the transmit line to the receive line so that outgoing signals can be redirected back into the source for testing.

OM and OS Designations

The designations "OM" and "OS" stand for Optical Multimode and Optical Singlemode respectively. They were first defined in the ISO/IEC standard covering premises cabling and classify optical cable according to wavelength and bandwidth.

The chart below compares the different fiber types.

Table 1: Fiber Optic Cable Types

  Fiber Type Core Diameter (µm) Jacket Color Wavelength Overfilled Bandwidth (@850nm) Effective Bandwidth (@850nm) Multimode OM1 62.5 Orange 850nm
nm 500MHz &#; OM2 50 Orange 850nm
nm 200MHz &#; OM3 50 Aqua 850nm
nm MHz MHz OM4 50 Aqua 850nm
nm MHz MHz OM5 50 Lime Green 850nm
953nm
nm MHz MHz Singlemode OS1/OS2 8.3 or 9 Yellow nm
nm &#; &#;

Multimode Bandwidth
In multimode fiber, light takes different paths (modes) as it travels down the cable. The paths that are closer to the center of the core are shorter so, all things being equal, light that takes these paths will take less time to travel the length of the cable. Multimode fiber compensates for this by slowing down the shorter paths and allowing longer paths to move faster so all modes arrive at the receiver at the same time. Of course, this is an ideal situation. In reality, modes arrive at slightly different times causing the light pulses to spread out and making it harder for the receiver to interpret the signal.

Overfilled vs. Effective Bandwidth
Older multimode cables use Light Emitting Diodes (LEDs) as their light source. These LED sources "overfilled" the fiber by using all available paths. Overfilled Launch (OFL) Bandwidth is a measure of the data transmission capacity of cable with an LED source, and is used with legacy fiber cable running at speeds of less than 1 Gbs.

Faster networks require a more focused light source and it came in the form of Vertical Cavity Surface Emitting Laser (VCSEL), pronounced "vixel", a semiconductor that omits a laser beam perpendicular to its surface. Not only was the beam narrower and resulted in lower signal dispersion, VCSELs were also cheaper to manufacture and more power efficient. VCSEL light sources did have one problem though. The light they produced was not uniform across the whole cable core. In essence, the core was "underfilled", with some modes carrying a stronger light pulse than others. It also meant that Effective Modal Bandwidth (EMB) rather than OFL had to be used to measure the performance of multimode fiber.

Comparing Multimode and Singlemode Speeds and Distances

Table 2: Fiber Optic Cable Speeds and Lengths

Fiber Type Fast Ethernet 10/100 Gigabit GbE 10 Gigabit 10GbE 40 Gigabit 40GbE 100 Gigabit 100GbE 400 Gigabit 400GbE 40 Gigabit SWDM4 100 Gigabit SWDM4 OM1 m 275m 33m &#; &#; &#; &#; &#; OM2 m 550m 82m &#; &#; &#; &#; &#; OM3 m 800m 300m 100m 100m 70m 240m 75m OM4 m m 400m 150m 150m 100m 350m 100m OM5 m m 400m 150m 150m 150m 440m 150m OS1/OS2 40km 100km 40km 40km 40km 10km &#; &#;

What Is SWDM?
Shortwave Wavelength Division Multiplexing (SWDM) transmits data over a cable using different wavelengths in the 850 to 953 nm range. SWDM4 transceivers use four light sources operating at different wavelengths to produce a multiplexed signal which is transmitted over two-fiber duplex MMF cable. Increasing bandwidth by using wavelength instead of additional fibers reduces cost and allows 40G and 100G data transmission rates over existing two-fiber cable.

SWDM4 works with legacy 10G OM3 and OM4 duplex MMF, as well as the newer OM5 wideband multimode fiber (WBMMF). OM5 is specifically designed to support SWDM4 wavelengths in the 850-953 nm range.

Fiber Optic Cable Termination

Unlike copper category cable that uses the ubiquitous RJ45 connector regardless of cable type, glass and plastic fiber optic cable can be terminated using a variety of connector types. Connector choice is determined by the equipment and the requirements of the application, including the anticipated number of mating cycles and the amount of vibration.

Singlemode fiber requires a clean, precisely aligned transceiver that injects light into its small core with sub-micron accuracy. By contrast, multimode fiber is a little more forgiving.

Ferrule Connector (FC)
The FC was the first optical fiber connector to use a ceramic ferrule. These connectors precisely position and lock the fiber core relative to the transmitter and receiver. FC connectors have been largely replaced by the cheaper and easier to install SC and LC connectors but are still preferred in high vibration environments due to their screw-on collet.

Straight Tip (ST)
ST was at one time the most common fiber optic connector for both singlemode and multimode fiber. It features a bayonet-style twist lock connector and is inexpensive and easy to install. It is still used in industrial and military applications but elsewhere, it has been largely replaced by smaller form factors.

Subscriber Connector (SC)
SC connectors have a reliable snap-in locking mechanism that latches with a simple push-pull motion. They are an inexpensive, durable option rated for 1,000 mating cycles. This connector is used in simplex and duplex (shown) configurations. SC connectors have been mostly replaced by LC connectors in corporate networks.

Mechanical Transfer Registered Jack (MT-RJ)
This Small Form Factor (SFF) connector is used with multimode fiber. It is easy to terminate and install, and its smaller size allows twice the port density of ST or SC connectors. It is similar in design and operation to a RJ45 connector, making it ideal for Fiber&#;to-the-Desktop (FTTD) applications.

Lucent Connector (LC)
The LC connector was designed to address complaints that ST and SC connectors were too bulky and easily dislodged. LC connectors have a footprint approximately 50% smaller than the SC connector. Thanks to this small size and secure latching feature, it is widely used in data centers and telecom switching centers where packing density is critical.

Multiple-Fiber Push-On/Pull-Off (MTP/MPO)
The MTP/MPO connector has a horizontal, multi-fiber interface designed specifically for use with high-bandwidth QSFP-DD transceivers. The connectors are about the same width as SC connectors but can be vertically stacked in patch panels and switches. They are ideal for high bandwidth applications such as cloud services and core data centers.

Corning/Senko (CS)
The new CS connector is 40% smaller than a standard LC duplex connector, making it ideal for very high-density 200G and 400G networks utilizing the QSFP-DD and OSFP transceiver interfaces. The connector features a push/pull tab and a spring-loaded zirconia ferrule.

Fiber Optic Cable Jackets

Jacket Material

Most indoor fiber optic cables use a low-cost, fire resistant polyvinylchloride (PVC) jacket. Some installations (e.g. confined spaces, but not risers or plenum) may opt for the more expensive Low Smoke Zero Halogen (LSZH) jacket, which is made of thermoplastic or thermoset compounds and offers superior flame retardant and produces little smoke or toxic fumes when burned.

Polyethylene (PE) is preferred for outdoor applications due to its resistant to moisture and sunlight (UV rays), abrasion resistance and flexibility over a wide range of temperatures.

Jacket Color

Colored jackets and connectors are used to identify the mode and OM rating of indoor and military cables, making it easy to identify at a glance the capabilities of a cable and ensuring that installers use the correct cable type for each connection. Outdoor cable jackets are typically black so they can resist damage from the sun, precluding the use of any color coding.

Color code standards and conventions specified in TIA-598D are shown in the table below. Jackets are also printed with additional information about the cable. For example, the jacket of an OM4 multimode cable with core dimensions of 50/125 and a bandwidth of 850 nm laser-optimized might be labeled &#;OM4 850 LO 50 /125".

Mode Cable Type Jacket Color Connector Color Multimode OM1 Orange Beige   OM2 Orange Beige   OM3 Aqua Beige   OM4 Aqua Light Green   OM5 Lime Green Light Blue Singlemode OS1/OS2 (PC/UPC) Yellow Blue   OS1/OS2 (APC) Yellow Green

Fire Rating

The National Fire Protection Association's National Electrical Code (NEC) defines levels of fire resistance for fiber optic cables. Indoor fiber installations are typically classified as plenum, riser or general purpose. Cables installed in plenum spaces and risers must meet standards for flame spread and smoke production outlined in NEC Article 770 and the UL Standard for Optical Fiber Cable.

UL defines the following optical-fiber cable types:

• Optical Fiber Nonconductive Plenum (OFNP)
• Optical Fiber Conductive Plenum (OFCP)
• Optical Fiber Nonconductive Riser (OFNR)
• Optical Fiber Conductive Riser (OFCR)
• Optical Fiber Nonconductive General Purpose (OFNG)
• Optical Fiber Conductive General Purpose (OFCG)

Application Nonconductive Conductive USA Test Acceptable Substitute General Purpose
All areas that are not plenum or riser on the same space or floor OFNG OFCG UL (OFNG) Riser or Plenum Rated cable Riser
A vertical space, typically inside walls and between floors OFNR OFCR UL (OFNR) Plenum Rated cable
Space above and below floors typically occupied by heating and air conditioning ductwork OFNP OFCP UL 910 (OFNP) No substitute

What's the difference between conductive and non-conductive fiber optic cable?
Non-conductive cables contain nothing that could carry electrical current. Conductive cables include metallic strength members, sheathing or other metal components that could potentially carry an electric current, even though that is not the intended purpose.

Note: Fire regulations vary from country to country. In the US, Article 770 of the National Electrical Code governs installation and testing of premises fiber cabling. In Europe, this falls to the IEC/CEI although individual countries may have their own standards organizations, such as the British Standards Institute (BSI) in the UK.

Fiber Optic Cable Performance

Optical Return Loss

When a pulse of light reaches the end of the fiber core, some percentage of light is reflected back towards the source. This Optical Return Loss (ORL), expressed in decibels (dB), only affects fiber with a laser light source and can reduce data transmission speeds. Singlemode fiber, and multimode fiber with a VCSEL light source, are sensitive to ORL. Older multimode fiber with an LED light source is not subject to ORL.

Are Optical Return Loss and Back Reflection the same thing?
ORL and Back Reflection are often used interchangeably but they are actually different. ORL is the total power lost from all system components, including the fiber itself. Reflected power is only one component of ORL.

Optical Return Loss can be minimized by ensuring that ferrules are clean and connectors are properly mated. It can also be reduced by choosing fiber optic cable with end-faces that are shaped to optimize the physical interface. Original fiber connectors had ferrules with a simple flat face, leaving a relatively large area that could be damaged with repeated mating. Physical Contact (PC)connectors are polished to a slightly rounded surface to reduce the size of the end face. The end face of Ultra Physical Contact (UPC) connectors have an even greater radius so the fibers touch at the apex of the curve near the fiber core.

The ferrules of an Angled Physical Contact (APC) connector are cleaved at an angle between 5 and 15 degrees. The angle directs the reflected light out of the core resulting in a lower ORL value.

Insertion Loss

Insertion Loss refers to the amount of light lost between two fixed points in the fiber and is measured in decibels (dB). Insertion Loss can occur when fiber is terminated with a connector or spliced, and is often the result of fiber core misalignment, dirty ferrules or poor quality connectors. The combined insertion loss of all system components should be within the limits specified in the link-loss budget agreed with the installer.

Fiber Cable Installation FAQs

What is the minimum bend radius for fiber optic cable?
For a cable that is not under pulling tension, the minimum radius should not be less than 10 times the cable diameter. For example, a multimode cable with an outside diameter of 3.0 mm has a minimum bend radius of 30 mm. The bend radius for a cable under tensile load may be greater. Refer to the cable's spec sheet for details.

What is the maximum tensile rating (pulling force) for fiber optic cable?
During installation, a fiber optic cable may be stressed when it is pulled through ductwork and around bends. Even pulling a cable from the payoff reel can potentially cause damage. After installation, cables can also be subjected to sustained pulling forces, for example, at cable drops or when run through risers.

The maximum tensile rating of a fiber optic cable is the highest pulling force that the cable can be subject to before the cable's fibers or optical properties are damaged. The cable manufacturer will typically provide two values: maximum tensile rating during installation and maximum tensile rating while in operation.

Fiber optic cable should ideally be pulled by hand in a smooth, steady motion. It should never be jerked, pushed or subjected to excessive twisting.

What is a Fiber Traffic Access Point (TAP)?
A passive fiber Traffic Access Point (TAP) allows network managers to monitor live network traffic without affecting performance on the primary link. When used with a traffic monitoring system, TAPs can be used to monitor service quality, enable usage billing and detect security breaches.

Key TAP Features

• No Latency - Fiber TAPs passively divert a fixed percentage of the light energy without introducing any additional latency into the network.
• 100% Packet Capture - TAPs pass a complete copy of all duplex traffic to monitoring and security appliances.
• One Way Signaling - TAPs protect the production network from security breaches by only allowing data to flow in one direction, from the network to the monitoring device.
• Split Ratio - this refers to the percentage of the signal that is split off for monitoring. A typical ratio is 70/30, meaning 70% of the signal remains on the primary link and 30% is sent to the monitor.
• Zero Configuration/Reliable Operation - Passive TAPs require no configuration, no management and no external power. They are easy to install, are completely transparent to the network and do not represent a potential point of failure.

Fiber optic cable vs. copper cable: which is the best?
Fiber optic cables have several key advantages over traditional copper cables:

• Higher Bandwidth and Speed - Fiber optic cables can support higher data rates, and hence can carry more data than copper cables of the same diameter. This translates to higher speed and bandwidth, which is particularly beneficial for internet, television, and services.
• Longer Distance - Fiber optic cables can transmit data over much longer distances without requiring signal boosters. The light signals in fiber optic cables don't degrade as quickly as electrical signals in copper cables, allowing data to be sent over longer distances without loss of quality.
• Better Signal Quality - Because fiber optic cables use light rather than electrical signals, they are less susceptible to electromagnetic interference. This can improve the quality of the data transmission, reducing errors and improving reliability.
• Security - It's more difficult to tap into a fiber optic cable to intercept the data it's carrying. The data is transmitted as pulses of light, which can't be easily intercepted without disrupting the entire communication link.
• Size and Scale - Fiber optic cables are thinner and lighter than copper cables. This makes them easier to install and allows more cables to be packed into the same physical space, which can be a big advantage in environments where space is at a premium.
• Durability - Fiber optic cables are more resistant to temperature fluctuations and are water-resistant, making them suitable for a variety of environmental conditions. They also don't corrode like copper cables can.
• Safety - Unlike copper cables, fiber optic cables do not conduct electricity, so they can be installed in areas with high electromagnetic interference, such as next to industrial equipment. This non-conductive nature makes them safer in terms of fire risks as well.

While fiber optic cables have many advantages, they also have some disadvantages compared to copper cables, such as typically being more expensive and requiring specialized skills to install and maintain. However, the benefits often outweigh these downsides, especially for applications that require high speed or long-distance data transmission.

What is fiber internet?
Fiber internet, often referred to as "Fiber to the Home" (FTTH) or "Fiber to the Premises" (FTTP), is a type of high-speed broadband internet service that transfers data via fiber-optic cables. These cables are less susceptible to interference or degradation, making fiber internet extremely reliable. It's also capable of delivering much higher speeds, making it perfect for speed sensitive business activities or online gaming.

Fiber optic internet can also provide "symmetrical" speed, meaning that the upload speed is the same as the download speed. This is a significant advantage over many traditional internet services, where upload speeds are often much slower than download speeds.

Do I need a fiber patch cable to connect my computer to a fiber internet?
Fiber To The Home (FTTH) or Fiber To The Premises (FTTP) service usually terminates at a device known as an Optical Network Terminal (ONT), which is installed at your home or business by the Internet Service Provider (ISP). This ONT converts the optical signal from the fiber cable into an electrical signal that your devices can use.

In most residential or small business situations, the ONT will typically have an Ethernet output that you can connect directly to a computer or, more commonly, to a router that provides network connectivity to multiple devices. This is often done with an Ethernet patch cable (Cat6a or higher), not a fiber patch cable.

However, in certain enterprise or high-performance computing situations where a device has a fiber-optic network interface card (NIC), you could potentially use a fiber patch cable to connect the device directly to a fiber network.

Why Buy from Eaton?

We know you have many brands to choose from. On the surface, they may all seem alike. It's what you don't see that makes the difference. With Eaton, you get solid engineering, proven reliability and exceptional customer service. All our products undergo rigorous quality control before they are offered for sale, and independent testing agencies verify our products meet or exceed the latest safety and performance standards. Our commitment to quality allows us to back our products with industry-leading warranties and responsive customer service. It's the Eaton difference.

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