Fiber Optic Blog

MPO Test Set Allows Quick Testing and Polarity Verification

MPO cables, which are typically made with ribbon or micro-distribution cable, make up a substantial share of today’s optical industry. It’s understandable because of the fact that they allow for the high speed transport of optical data in a condensed manner. This is ideal because as one can imagine, space is sold at a premium within the data center environment. In addition to providing many advantages to high-speed networks for their owners and installation technicians, MPO cable assemblies are a no-brainer for higher end bandwidth systems. When it comes down to it, they are primarily used to deliver very large amounts of sensitive data to customers consistently, making them the most reliable form of data transport with high redundancy. With all of these advantages, the 12 and even now 24 fiber MPO-style connectors are more and more becoming the preferred connector within the fiber optic industry.

With this all being said a well known challenge has been to accurately test these cables not only for dB loss but for their “polarity” configuration as well. An MPO cable’s polarity refers to the way the fibers are arranged inside the cable. There are typical polarities used within the industry; “A”, “B”, or “C” polarities. For example, Type-A polarity (straight through) is simple – fiber 1 goes to fiber 1, 2 to 2, 3 to 3 and so on. Type-B polarity (inverted) is laid out for fibers 1 to go to fiber 12, 2 to 11, 3 to 10, and so on. Type-C polarity (twisted pair) is arranged for fiber 1 goes to fiber 2, 2 to 1, 3 to 4, 4 to 3, and so on.

Traditionally, to perform attenuation (loss) testing for MPO cables the user would have to use an MPO to LC breakout cable, use a traditional power meter and test each fiber one at a time through each LC connector. Also, all polarity testing would have to be done manually as well with a visual fault locator or continuity tester. This leads to longer test durations, which means higher labor costs and an overall headache when trying to keep track of what polarity and what fiber number was for which cable.

As MPO cables have increased dramatically in popularity over the last several years. The market has evolved to produce a tester that can accommodate the growing need to test and certify these cables faster and easier. The MPO loss test sets can do all of the core functions that are demanded by the industry: Polarity check, dBm power referencing , “pass/fail” dB loss testing, continuity check, and reporting software that can certify a newly installed MPO cable. This product has cut the testing time down from several minutes to several seconds!

Once you have determined the polarity type, referencing the power meter is done essentially the same way as you would with a traditional power meter/light source set up. Attach your reference cord(s), press the zero/reference button, attach your test cable, select the polarity of the test cable and within about 10 seconds you have your entire MPO cable certified for loss and the passing results can then be stored and are ready to be organized into a report on your PC for you and the customer.

With the ability to save up to thousands of tests and define your own pass/fail thresholds, you have the flexibility to test your MPO cables under just about any situation that you or your customer needs. When it comes to reporting the results, each file slot on the meter contains results for the 12 channels (fibers) and a pass/fail mark is visible so you can easily identify and organize your test results. If you choose, you can export hundreds of files in seconds. Then the PC software program allows you to customize your header information. You can include details such as test location, date/time, operator, company, etc.

The fiber optic industry offers MPO loss test kits for singlemode as well as multimode cables that are of great value to a whole range of fiber optic technicians. The multimode set typically includes the power meter and 850nm light source with appropriate reference cables. If you are testing a large amount of cables for multimode it’s important to make sure that your multimode source is “encircled flux compliant”. Because of the nature of how multimode LED sources launch into a cable, there are other modes of light that exist in the cladding of the fiber for the first few meters which can invalidate the power reference(dBm) . This is traditionally why mandrels have been used for MM testing, however encircled flux compliant sources and/or reference cords are designed to allow for more consistent referencing, thus meaning a lower variation in insertion loss results test after test. As for the Singlemode kits, they can include a 1310nm light or a 1550nm light source. Power meters and light sources can be obtained separately as well.

When it comes to what is expected by customers and clients for MPO testing applications, it’s important to note that it isn’t just insertion loss testing and polarity verification that is needed; there are other tools that are used to maintain and properly certify these types of cables. Because insertion loss is a main concern in testing and most of the loss of the cable is coming from the connectors themselves, MPO inspection probes are gaining in popularity to ensure the MPO end face is clean. This goes hand in hand with the proper cleaning consumables to keep the 12 -24 fiber end faces clean and defect free.

Most MPO test sets today work in conjunction with a MPO capable visual inspection probe with pass/fail software that adheres to the IEC industry standards. This ensures the customer that the cables were inspected and passed when installed and tested. The images can be uploaded into a report in the same fashion as typical single fiber images can be.

As far as cleaning goes, there is a whole range of cleaners one can use. The most effective are the “push-click” style cleaning pens; which can clean both male and female MPO connectors as well as into mating sleeve bulkheads. There are also gel pads that the user will press the connector into and when the connector is removed from the gel pad any debris that was on the connector endface remains in the gel, leaving the endface clean.

Typical MPO test kits would include: MPO power meter, MPO light source(s), reference cords, mating sleeves, A.C. power adapters, reporting software, etc. Separate additional accessories to assist in maintenance: MPO connector push-style cleaner, MPO gender change tool, MPO/LC breakout cable, extra reference cords and mating sleeves.

As you can see the MPO style connector isn’t going anywhere and today the industry offers options that allow technicians to properly verify, test, and certify all aspects of their MPO cable assemblies. Whether it be polarity or continuity verification, insertion loss testing, or end face inspection, the tools exist to confidently certify these assemblies built for high density and high bandwidth applications.

Advantages of Jetting Fiber Optic Cable Over Traditional Pulling

What are the advantages of blowing or jetting fiber optic cable vs. traditional pulling?

Pulling and blowing are the two primary fiber installation methods. But each of these techniques can impact the longevity, performance, and return on investment (ROI) of a fiber optic network. If you take into account the fragility of glass or fused silica during installation, distance to be covered, efficiency, and costs, you may see that jetting (blowing) offers many advantages over traditional cable-pulling techniques.

An Overview of Fiber Optic Cable Installation Methods

• Pulling: It involves pulling the fiber optic cable through pre-installed underground or aerial ducts. You can pull the cable manually or using a reeling machine. You’ll also need a pulling tape to haul the cable while measuring the distance covered.

• Blowing: With this technique, high-speed air pressure pushes fiber optic cables through standard ductwork or microduct systems.

Here are the reasons why cable jetting is superior to traditional pulling methods:

Minimal Risk of Tension Damage

Each brand of optical fiber cable has a maximum tensile strength. But in pulling, there’s a risk of straining the cable beyond its limit, which can compromise the fiber’s performance and cut its service life. Unchecked resistance forces, such as friction, on the sidewalls of cables and ducts, can also cause damage during a “pulling” installation.

In contrast, jetting involves little or no pulling, which significantly minimizes strain on the fiber optic cable. You can not only configure the system’s hydraulic pack or air-compressing equipment to control airflow inside the duct but also monitor the conduit and fiber to minimize damage.

To minimize friction during cable jetting, consider applying lubricants meant for the method. Ducts with low-friction interior walls may also help.

Suitability for Long-Haul Fiber Optic Networks

Pulling isn’t the best option for placing outside plant (OSP) fiber optic cable. With the technique, there’s always a high possibility of pulling the cable into conduit bends. And as bend angles continue to accumulate, it becomes increasingly difficult to optimize pull length. The bad news is that ducts for cross-country fiber optic networks can have many bends.

As such, pulling is ideal for short-distance fiber optic cable deployment. Distance will vary from one manufacturer to another and cable jacket material plays a role too.

With high air speed blowing fiber optic installation, however, conduit bends and undulations aren’t as much of an issue as they are with traditional cable-pulling techniques. The blowing force doesn’t pull the cable into a duct bend. It instead pushes it smoothly around every turn or curve.

In other words, the duct route geometry doesn’t impact installation distance in this case. Consequently, air-assisted installation lets you place fiber optic cable thousands of feet between jetting sites. That’s why it’s suitable for OSP fiber deployments, for example, telecommunication, CATV, and internet networks.

Reduced Costs

Cable jetting equipment and ductwork may be initially expensive. But you can amortize these upfront costs depending on current needs, and your initial investment may pay off in future savings on upgrades. For example, you don’t have to invest in redundant higher fiber counts when you can cheaply upgrade capacity in tandem with changing requirements.

Likewise, “pulling” is more labor-intensive than the blowing method. The technique involves more equipment movement, and it may require the positioning of placing tools at intermediate points and both ends of long OSP runs. Additional workers and extra equipment translate to higher installation costs. Cable jetting requires fewer cabling technicians, however.

Keep in mind that air-assisted optical fiber installation minimizes the number of splices needed. Cables installed this way don’t usually require “figure-eight” looping to prevent twisting every time duct changes direction. Since the approach has fewer intermediate-assist placement operations, it limits the number of handholes and other access points required along the cabling route.

Suitability for Microduct Installation

Jetting is very effective in pushing fiber optic cable through microducts. With the blowing method, you can place microduct cable in continuous lengths. The technique is most suitable for modern optical fiber cables that tend to contain bare fibers, and sometimes reduced cladding diameters, both of which contribute to decreased outer cable diameters.

The thinner a fiber optic cable is, the larger the number of fibers you can place in specific innerduct. As such, jetting is the best installation technique when you wish to make the most of the available duct capacity. It also allows you to work with small but flexible fibers that go through multiple microduct twists and turns over long distances with near-zero bend losses.

Additionally, when setting up microducts for fiber optic cable jetting, you may include redundant ductwork to accommodate new fiber in the future as required. This way, you avoid the unnecessary costs of placing dark fiber, which may become obsolete sooner than anticipated.

Appropriate for Removal of Old Fiber

Pulled fiber optic cable may be difficult to remove when no longer needed. The presence of old and unwanted cables in mission-critical physical pathways may limit your ability to optimize your optical network capacity or even upgrade to higher-performance fibers.

But after installing optical fiber by cable jetting, you may easily remove it by the same approach when necessary. You may be able to reuse the removed fiber optic cable since the removal process is gentle enough to minimize or avoid damage.

Quick Installation

Cable jetting is faster than the “pulling” method. The pushing device can move fiber optic cable at speeds of 350 feet per minute or higher. With the air-jetting technique, you can quickly push cables through pre-installed innerduct or underground ductwork. But in most cases, you can only pull fiber at a rate of 100-200 feet per minute, or even slower.

Less Disruption

Choose cable jetting to upgrade your optical fiber with minimal interruption to ongoing workflows or operations. The cable-pulling approach is more disruptive.

Choosing the Right Fiber Optic Cable

There are so many fiber optic cable options available that one might wonder where to start. This article will set you on the right path in the decision process. Let’s begin by focusing on the broad categories of fiber optic cable. Below you can make “either/or” decisions. A handy reference chart that summarizes key cable features can be found below.

Multimode or Single Mode?

Multimode Cable – Applications: Multimode fiber is used to transport high volumes of data over relatively short distances (compared to single mode fiber). Common applications include Data Centers and other Local Area Network (LAN) applications. Note that multimode distance capabilities have increased over the years. Multimode fiber cable now offers an economical alternative to single mode cable for certain applications. Design: Multimode cable has a relatively large core (either 50 or 62.5µm) that enables multiple streams of data to be transported simultaneously.

Single Mode Cable – Applications: Telcos and CATV companies use single mode cable to transport signals over long distances. Business campuses and other institutions also use single mode cable for longer cable runs, such as links between buildings. Design: The core diameter of single mode fiber is so small (9µm) that it permits only one mode of light to pass through it at any given time. This characteristic reduces attenuation and enables light to be transmitted over great distances. While the purchase price of single mode cable is less than multimode cable in general, single mode transceivers and network interfaces are generally more expensive than those used for multimode systems.

Simplex or Duplex?

Applications: Simplex and Duplex cables are typically used for fiber optic patch cables and desktop installations that don’t require a high fiber count. Design: Simplex cables contain a single 900µm coated fiber or a combination of a 900µm coated fiber surrounded by an aramid yarn strength member with an outer jacket diameter varying between 3, 2, 1.8 and 1.6mm. Duplex cables contain two 900µm coated fibers surrounded by an aramid yarn strength member with an outer jacket diameter varying from 3, 2, 1.6 and 1.2mm.

Loose Tube or Tight Buffer?

Loose Tube Cable: Applications: Loose tube cable is ideal for use in long distance outside plant applications that require a high fiber count. The cable is designed to withstand harsh outdoor environments; the cable’s unjacketed fibers are free to expand and contract with temperature changes. Design: Fibers within loose tube cables are surrounded by a water blocking component (either gel or a dry water-blocking material). Although loose tube cables are engineered to withstand damp outdoor environments, they are not designed to be submerged in water, but can come in contact with water. Terminating Loose Tube Fibers – The fibers within the gel-filled tubes of the cable have a very thin acrylate coating which is 250µm in diameter. Before terminating, the fibers must be put into small plastic tubes (called a breakout kit or box). The tubes protect the thin fibers and make them easier to handle when terminating and connecting to network equipment.

Tight Buffer Cable: Applications: Tight buffer cable is typically used indoors. A tight buffer (cable jacket) encapsulates each fiber. The 900 micron buffer enables the fibers to be directly terminated without requiring a breakout kit, which saves substantial time. These cables do not typically provide protection from water migration and do not isolate fibers well from the expansion and contraction of other materials due to temperature extremes. Tight-buffered cables, often called premise or distribution cables, are ideally suited for indoor-cable runs. Design: Tight buffer cables have two protective coatings; a 900 micron PVC jacket and 250 micron acrylate coating, all encased in an outer PVC jacket.

Distribution or Breakout?

Distribution Cable: Applications: Distribution cable is ideal for networks that terminate multiple fibers at a common location, such as a patch panel or communications closet. Fibers within a distribution cable have their own 900 micron individual cable jackets. This space-saving feature enables up to 144 fibers to be bundled within the cable. Fibers in a “Micro Distribution” cable do not have the 900 micron tight buffered PVC jacket, instead they contain color coded 250 micron acrylate coated fibers. Because of the decreased diameter of the individual fibers in the cable, a micro distribution cable may contain up to 432 or more fibers. A disadvantage of micro distribution cable is that the unjacketed fibers require the use of a breakout kit for termination. Design – Distribution cable contains a number of 250µm – 900µm fibers that are color-coded for easy identification. The cable includes an aramid yarn strength member and a thick outer jacket that provides protection and strength during cable installation. If required, the cables can be purchased with interlocking armor.

Breakout Cable: Applications: Breakout cable is ideal for applications where fibers are connected directly to equipment, including local hubs. Also, the robust design of breakout cable makes it well suited for use as drop cables. Design – Breakout cable differs from distribution cable in that each of the fibers in a breakout cable is 900 micron tight buffered and surrounded by aramid yarn all encased in a 2mm or 3mm PVC jacket. Then all of these 2 or 3mm jacketed fibers are encased in an outer jacket. This additional jacketing can save substantial time and installation cost, especially if the fibers are being terminated with connectors. One disadvantage of breakout cable is that the fiber jackets take up room within the cable, so breakout cable cannot contain as many fibers as distribution cable. Fiber counts for breakout cable are typically 2-24 fibers (maximum is 48 fibers).

Choosing Fiber Optic Connectors for Your Application

Optical Loss – A Critical Consideration

Whether a fiber optic connector must interface with a simple transmitter or the latest ROADM multiplexer, the connector interface is of critical importance because of its unique loss characteristics. To illustrate this point, consider the difference between connectors for fiber optic cable vs. copper cable.

Power loss for both types of connectors are stated in decibels (dB). That’s about where the similarity ends, because copper connectors and fiber optic connectors have opposite loss characteristics.

Copper connectors produce negligible loss when compared to losses produced by the copper twisted-pair cable to which they are attached. With fiber, the exact opposite is true. In a typical fiber optic system, fiber optic connectors produce far more loss than that produced by the fiber optic cabling. That’s why careful connector selection, particularly in regard to a connector’s loss specifications, is so crucial.

Other considerations that affect connector loss involve how the connector is joined to the field fiber, and how meticulously fiber optic connectors are cleaned and inspected prior to coupling.

Narrowing the Field

There are nearly 100 styles of fiber optic connectors, so choosing the right one for a particular application might seem daunting. However, this connector guide simplifies the selection process by focusing on the most useful and popular connector styles currently available.

In many cases, the types of connectors that you must use are dictated to you, especially if you are upgrading a legacy system. In that case, you may have to use the same type of connectors that are already in place in order to accommodate existing equipment and cabling. Even so, it’s a good idea to know the loss characteristics and other attributes of the connectors that you are working with. For example, a connector’s “insertion loss” specification relates to optical loss that results from differences in concentricity, ferrule endface geometry or other irregularities. Knowing the connector’s insertion loss specification can be useful when testing.

In some cases, such as a new install, connectors may or may not be specified. If connectors are not specified, you will likely be presented with a loss budget for cabling and connectors that you must adhere to. In this case, you have to give some serious thought to selecting the best connectors for the job. You also have to take into account the connector termination method (e.g. fusion splicing, epoxy, or mechanical termination) because this can have a significant impact on optical loss and back reflection characteristics.

Choosing The Right Connector

The following are considerations for choosing fiber optic connectors for your application.

Talk Like a Pirate….ARRG!

ARRG stands for Alignment, Ruggedness, Repeatability and Geometry. When choosing connectors, this memory aid will help you recall desirable connector qualities. The following attributes apply to most connector styles.

Alignment – A quality connector will keep fiber properly aligned with the fiber to which it is mated. Proper alignment is especially critical for single mode fibers which have a very small fiber core through which signals are transmitted. Always buy quality connectors and mating sleeves from recognized manufacturers to ensure that connectors are manufactured to high tolerances and provide optimal alignment.

Ruggedness – Will connectors be installed in high-traffic areas? If so, a good choice are epoxy-style connectors, which have the fiber bonded to the ferrule. This resists optical disconnects caused by tugging, temperature changes and other external forces. As added protection, consider a spring-loaded “non-optical disconnect” connector, such as the SC connector or LC connector, which are specifically designed to prevent optical disconnects. For harsh outdoor environments, “hardened” connectors are available.

Repeatability – Will there be a number of occasions when your connector will be disconnected? If so, consider using a connector that is known for good “repeatability.” The term repeatability refers to the performance of any class of connectors that are known to provide consistent loss performance that varies by a relatively narrow margin. Such connectors are typically keyed, or contain a keyway feature that prevents ferrule endface rotation. Keyed connectors ensure that connectors that are uncoupled from one another maintain the same ferrule endface orientation when they are recoupled, resulting in connector losses that are predictable, consistent and “repeatable”.

Geometry – The shape of the connector ferrule endface has a major affect on interface loss. For example, UPC connectors have ferrules that have a domed endface surface to insure contact at the core of two mated fibers, which helps to reduce insertion loss. Other connectors have an angled ferrule endface (APC connectors) which helps to minimize back reflection by directing endface reflections away from the core of the fiber. Knowing how ferrule endface geometry affects loss is important when selecting connectors, especially if you plan to polish your own connectors. Polishing procedures vary for different endface geometries.

Now that you know the general qualities you are looking for, it’s time to choose a specific connector for your application. The following approach uses a simple 3-step process of elimination.

Step 1. Weed Out Connectors that Can’t Meet the Loss Budget – Loss budgets will usually have connectors and cabling losses broken out separately from the rest of the network. Except for very long fiber links, losses for fiber optic cabling are usually negligible, so you’ll want to focus most of your attention on choosing the right connectors. Begin by narrowing down your possible connector choices to those that can stay within the loss budget of your application. For each connector being considered, simply multiply the number of connectors required by the dB loss specified for that type of connector. Now add fiber-optic cable loss to that number. If you are still within loss budget, great. You can proceed to Step 2.***

***It is possible to be within the loss budget but still have connections that produce unacceptable levels of back reflection. An Optical Return Loss (ORL) Test Set can be used to measure the level of back reflection. Also, an OTDR is useful for identifying the location of high-ORL events such as defective splices and connectors so that corrective action can be taken.

Step 2. Consider Installation Time, Material Costs, and Skills Required – After narrowing your list down in Step 1, it’s time to consider the costs associated with each type of connector, including installation skills required. Will you have to put your best installers on the job?

Step 3. Your Own Preferences – After completing Steps 1 and 2, let’s say that you have narrowed your connector list down to two possibilities. Now you can use your own personal preference to make the final decision. Simply choose the connector with which you are most comfortable and proficient. This will increase your speed and productivity on the jobsite and help to ensure quality terminations.

Tip: When trying new connectors and termination procedures for the first time, do enough of them in the shop to become proficient. Experimenting in the field is never a good idea.

Why Use Splice On Connectors?

Prior to the introduction of fusion splicers, it was common for fiber optic installers to hand-polish connectors in order to minimize optical loss. For each connector, the process involved:

• Stripping the field fiber and using epoxy to glue the fiber within a connector ferrule.

• Slowly and meticulously polishing the fiber endface by using progressively finer grits of diamond “sandpaper.”

The objective was to achieve a smooth endface surface with the proper geometry required to minimize insertion loss. Even with all that effort, hand polished connectors fell short of factory polished connectors which had lower optical loss.

The fiber optics industry searched for a simpler and faster way to connectorize fiber. The first “solution” was to use factory polished connectors that could be purchased with attached lengths of fiber optic cable (pigtails). The idea was that the installer could simply fusion splice the end of the pigtail to the field fiber and be done with it. No hand polishing was required.

Cable Management and Space Considerations with Pigtails

While splicing connectorized pigtails provided a faster alternative to hand polishing, one drawback was that the splice required an external splice protection sleeve that had to be installed in a splice tray within a splice cabinet. So, what seemed like a simple and elegant solution turned out to be more complicated in terms of cable management.

Mechanical Connectors

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 -40dB reflectance. Also, most mechanical connectors available today require the purchase of a brand specific termination kit. These can be quite expensive. The connectors can also be expensive, with some costing as much as +$17.00 per connector. So, when you figure the cost of the kit and the connectors and then figure in the back reflection of the connection, mechanical connectors are a good choice to get a damaged connector replaced quickly to reduce network down time, but they are not a good permanent solution. It is highly recommended that the mechanical connector be replaced with a factory polished pigtail or splice on connector during the next service window.

The SOC Solution

More recently, splice on connectors (SOC’s) were developed to address the cable management and space considerations of connectorized pigtails. Instead of a long pigtail, the body of the SOC contains a short fiber stub (essentially a micro pigtail) to which the field fiber can be fused. Because the splice protection sleeve is contained within the connector assembly underneath the boot, there is no need for a splice tray, splice chips or splice cabinet.

SOC Advantages

Simplified Cable Management

As explained above, SOC’s greatly simplify cable management for any fiber optic network. SOC’s require no extra rack space and eliminate the need for slack cable management. This advantage is especially important for data centers and other high-density applications.

More Installer Options

Installers no longer have to rely solely on traditional pigtails or mechanical splicing to achieve quick connections in the field. SOC’s are fast to install, with the added advantage of achieving low-loss connectivity.

Easy to Install

Installing an SOC is essentially a three-step process:

• The installer slides the SOC connector components onto the field fiber. The components include a heat-shrinkable protection sleeve and connector boot.

• Using a splicer specific SOC holder on the fusion splicer, the installer places the field fiber adjacent to the exposed fiber stub on the splice on connector. The technician then fuses the field fiber to the fiber stub that protrudes from the back of the ferrule.

• After fusing, the installer heat-shrinks the protection sleeve and slides the connector boot into place.

Successful Splice Notification

All current model fusion splicers notify the installer when a successful splice has been achieved. This eliminates guesswork, enabling SOC’s to be installed by novices and experienced technicians alike. If you are in the market for a fusion splicer, be sure to choose a model that is capable of splicing SOC’s!

Cost Efficient

The prices of fusion splicers have come down significantly in recent years, which has contributed to the popularity of SOC’s. Although SOC’s cost more than standard epoxy and polish connectors, SOC’s save money because they are faster to install and require less technician training or expertise.

SOC Applications

• Data center installations

• Multi-dwelling unit (MDU) networks

• Campus environments

• Outside plant

• FTTDesk

• Cable TV backbone

• Anywhere that a fast, low loss connection is required. .

The 900um Cheetah SOC from FIS led the pack in being one of the first SOC’s brought to market.

• Return loss: APC >-65dB, UPC >-55dB and MM -35dB (typical)

• 20+ styles available: SM, MM(OM1 & OM2), 10Gig (OM3 & OM4)

• Available connector holders are compatible with many industry leading splicers including (but not limited to) FIS, AFL, Sumitomo and Fitel fusion splicers

• 900um strain relief boot protects splice point for easy cable management

Armordillo SOC

This splice on connector from FIS features a tough housing, an extended crimp sleeve and strong Kevlar bond to achieve superior pull strength.

• Termination for 1.6mm, 2.0mm and 3.0mm cable

• Return loss: APC >-65dB, UPC >-55dB and MM -35dB (typical)

• 20+ styles available: SM, MM (OM1 & OM2), 10Gig (OM3 & OM4)

• Extended crimp sleeve provides industry leading pull strength

• Jacket insert to fit 1.6mm, 2.0mm, or 3.0mm cable with the same connector package

SOC Capable Fusion Splicers

FIS offers a wide range of fusion splicers from the industry’s leading manufacturers including Fitel, AFL, Sumitomo and FlS. SOC capable fusion splicers are also available from the FIS Rental Department. Both desktop and hand held models are available.

What is the Purpose of a Power Meter & Light Source?

What is a Power Meter & Light Source?

A Power Meter & Light Source is a low cost way to certify optical fiber. These two pieces of test equipment are used to measure fiber optic light continuity, loss and lastly the actual strength of the optical signal.

Signal Loss

In fiber optics when a beam of light which carries a signal goes through the optical fiber the strength of that beam of light will diminish over distance. This means the signal strength becomes weaker. This loss of light power will affect the fiber optic network in a negative way. The loss of light power or attenuation of the optical fiber is caused by two issues, scattering and absorption of the light source. If the degradation is too great then performance of the network will be affected.

The following can be the cause of signal loss:

• Tight Bends in the Cable

• Dirty or Improperly Cleaned Connectors

• Too much Stress on the Cable During Installation

• Poorly Installed Connectors

• Improper Splicing Technique

• Poor Cable Quality

What Equipment is Needed to Conduct a Power Meter & Light Source Test?

A Power Meter and Light Source are a pretty simple piece of test equipment to use. An installer needs basic knowledge for cleaning fiber optic ends. The actual connection of the fiber to the test equipment is fairly straightforward. If you are familiar with handling fiber optics the test is very easy. If you are new to fiber optics this test should not present any issues. A simple short video explaining the test should be all you need.

Why use an OTDR in Place of a Power Meter & Light Source?

The Power Meter and Light Source are more limited than an OTDR. A Power Meter can only measure the received optical power. The OTDR can not only tell you there is a break is in the fiber, it can also measure the distance between the test point and the break. In addition, it is able to give you reflectance for each connector. Even though the OTDR can reveal additional information, the Power Meter and Light Source are still an important piece of optical fiber test equipment and their importance should not be underestimated when testing an optical fiber network.

How Does A Power Meter & Light Source Work?

By attaching a reference cable to the light source, power can be measured at the opposite end of the fiber optic cable. The signal is sent from the light source down the fiber. These two pieces of test equipment are used to measure fiber optic light continuity, loss, and lastly the actual quality of the signal. In short, it measures the power of the optical signal that has passed through the fiber cable from the light source.

Steps to Using a Power Meter and Light Source

Using the Power Meter & Light Source to test a fiber optic cable is relatively easy.

• First take the reference cord end face and clean it with 99% reagent grade isopropyl alcohol and lint free fiber optic wipes.

• Next plug the reference cord into the light source and select the wavelength you are testing. When testing a multimode cord attach a mandrel wrap to strip out the higher modes of light that can interfere with the test results. A mandrel wrap is not necessary for singlemode.

• Clean the other end of the reference cord and insert that end into the Power Meter. Now zero out the reference cord by hitting the “zero” button. After zeroing out, do not unplug the reference cord from the Light Source. Take the cord to be tested and clean one end, then attach the connector adapter. Clean the other end of the patch cord.

• Remove the reference cord from the power meter and attach to the test cord adapter, insert the other end of the test cord into the power meter. The reading on the power meter will give you the loss on the connector mated to the reference cord only. To get the loss reading on the other end simply unplug the test cord from the reference cord and switch the connectors. You have now completed the one cord reference test.

• For a two cord reference test attach a connector adapter to the reference cord and insert the other end to the power meter. Zero out the power meter. You are now ready to get a loss reading for the entire cord being tested.

• Take the test cord and clean both ends with the cleaning alcohol and wipes. Connect the test cord in between the two reference cords. The power meter will show a full cord reading for total power loss. Record your loss as needed.

What to Look for when Purchasing a Power Meter and Light Source

The Power Meter and Light Source or Optical Loss Test Set are must have tools for the fiber installer. While they are fairly simple tools to operate, care should be taken in choosing the Power Meter and Light Source as there are many models to choose from.

• Is the equipment easy to use or does it require a huge manual?

• Operation of this piece of equipment should almost be intuitive.

• Appearance is important. Is it easy to hold?

• There should be a minimal amount of buttons on the unit.

• Are screens easy to read? Is it backlit?

• Is the Power Meter and Light source calibrated?

• Does the manufacturer calibrate their equipment?

• Can they provide a calibration certificate traceable to NIST standards?

• Does the unit come with a protective carry case?

• What about battery life?

• Are adapter caps included?

• Does the kit include a dual wavelength multimode or single mode light source?

• Does it come with interchangeable adapters allow flexibility with reference cords?

As with any fiber optic test equipment, know the manufacturer. Find a reputable company that will stand behind their equipment. If you have questions about your choice, call or email the company and talk with a technical person that can help you decide which piece of test equipment best suits your needs. Remember, there are many manufacturers out there in the marketplace. Consider only those with reputable firms that have a good track record. One that can service and maintain your equipment if needed.

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