Author: Fiber-MART.COM

eShop of Fiber Optic Network, Fiber Cables & Tools

How to Test MPO Connectors for Top Performance ?

Multifiber push-on (MPO) connectors are becoming more and more popular because of their many advantages for high-speed network operators, owners and installation companies. They are used to connect the fastest links that deliver the most sensitive services and data to customers, enable high-speed interconnects and create redundancy. More and more, telcos are reconfiguring their central offices into data centers (CORDs) and deploying MPO cables with 12 or, increasingly, 24 fibers. In fact, MPOs are quickly emerging as the connectors of choice.

However, since the main source of loss in links is connector related, the failure to properly test and maintain MPO connectors puts the entire network at risk. In fact, without proper validation, CORD operators may end up having to pull the plug on critical lines for troubleshooting.

So, how can you ensure peak MPO performance? It all starts with testing. Let’s take a closer look at the three essential tests to ensure the quality of your link: polarity-type validation, continuity confirmation and connector inspection.

Testing polarity

Polarity simply refers to the way the fibers are arranged inside the cable. During installation, MPO connectors must be properly aligned and mated, which is not as simple as it sounds. Ensuring accurate polarity for MPO fiber array cables is a big deal and can be complicated, due to multiple polarity schemes available for these connectors and polarity flipping during connecting and installation.

Three different polarity types, corresponding to different cable structures, are used with MPO cables. Validating these helps you confirm their type, ensures that signals are traveling in the correct path and connections between the transmitting and receiving end are intact.

In testing polarity, your main goal is to make sure the right transmitter (TX) is sending signals to the right receiver (RX). To accurately send and receive data, MPO connectors must be properly aligned and mated. Bad coupling will impede signal transmission, as the signal could be sent in the wrong direction.

Undiagnosed polarity issues increase CAPEX and work for technicians (i.e., OPEX). Technicians may unnecessarily rip and replace expensive MPO patch cords, believing they are faulty, when in fact they simply did not have the expected polarity type. If polarity issues are not corrected before turn-up, then trying to pinpoint which cable connections have polarity problems after they have been installed becomes a frustrating and tedious guessing game.

Testing continuity

Confirming the continuity of a link ensures that there is no break and that light travels properly all the way to the end of the link. It’s a quick validation test that, when done during installation, can save a lot of potential troubleshooting later.

Testing connector cleanliness

Considering that 80% of network problems are due to dirty connectors, and the No. 1 cause of network failure is contaminated connectors1, it goes without saying that inspection and cleaning are critical.

With multifiber push-on connectors, inspecting and cleaning is particularly important because each port represents a potential point of failure. Additional fibers create more surfaces, which means there is a higher risk of contamination and failure. Bad connectors are a significant cause of loss, and the impact is ever greater for MPO links, where a single dirty or damaged connector can affect as many as 12 or 24 fibers.

How to clean MPOs

Inspect, clean, reinspect.

1. Inspect

Always inspect the connectors first. You don’t need to clean a connector if it’s already clean, as cleaning it might make it dirty. This is especially true for MPO connectors, which are highly sensitive. For example, for an MPO-24, dirt from the first row could potentially migrate to the second row while cleaning.

Make sure to inspect both mating connectors, as residue from a dirty connector will transfer to a perfectly clean connector once they mate.

2. Clean

If the connector is dirty, first try the dry method.

If the dry method fails to remove the dirt, try the hybrid cleaning method, which involves using a solvent.

3. Reinspect

Always dry your connector after using wet cleaning tools and always reinspect the connector.

Choosing high-performance tools for easy inspection

Given the popularity of MPOs, it’s important to know how to take full advantage of these powerful cables. Choosing the right testing tools and making sure your cables have passed the three essential MPO tests—polarity, continuity and inspection—are critical to turning up and maintaining efficient links. What’s more, to guarantee that your network is future proof and can meet the ever-increasing demand for bandwidth, it is crucial to ensure connectors are in good condition.

Why should Use the Right Polarization Maintaining Fiber

Fused Coupler is a type of optical fiber that is used to split high power single line polarized light into multiple directions without disturbing the line at the state of polarization. This fiber is also used as a power tap to monitor signal power in a PM fiber system. A fused coupler is widely used in PM fiber interferometers, power sharing in polarization sensitive systems, and signal monitoring in PM fiber systems.

Couplers are generally divided into two categories- passive couplers and active couplers. The passive couplers are able to redistribute the optical signal without making optical to electrical conversion while active couplers electric devices used to split or combine signals electrically using a device called fiber optic detector and sources for input and output.

Based on applications, the couple has different types. So to make sure you choose the right coupler, it is crucial to know about them.  Here, we will shed light on some of the most important ones that are widely used today.

T coupler

Also, called Y coupler, it is a three port device and mainly used for power monitoring. It is also used for splitting the power input into two equal outputs.

Tree coupler

Its main work is to split the single input into multiple outputs. It is used as a combiner to combine multiple output signals.

Star coupler

It is pretty well different from the first two. Unlike them, this coupler has multiple inputs and multiple outputs. The fibers radiate from the central point likes a star. And this is why it is called star coupler.

Wavelength selection coupler

Also known as WDM (wavelength division multiplexer, wavelength selection coupler splits the signal based, not on power.

Having a look at the types of couplers and their applications, it is quite clear that each of them has a different application. And so they perform well in a particular situation and meet a particular need. If you are looking a coupler, it is very important to choose the one that best meets your needs.

And the best way to know which one will work best for you are looking at your needs. Yes, first of all, you should figure out your requirements. This will make it easy for you to come out with the right option without wasting your time.

Features of top couplers for polarization-maintaining

In addition to the types of a coupler, the features of coupler also play a vital role in selecting. Here are some of the top features that you must consider when looking for the one for you. A quality fused coupler has:

Low insertion loss

• High extinction ratio

• Compact In-Line Package

• Available for Slow or Fast Axis Operation

• High Stability and Reliability

Whether you are looking for couplers for the use of Fiber Optic Instruments, Fiber Amplifiers, Fiber Sensors, or Coherent Detecting devices, choose the one, keeping in mind the above features. Also, make sure to buy only from top suppliers of Polarization Maintaining Fused Couplers in China.

Brief Introduction to Polarization Maintaining Isolators

Polarization maintaining isolator which ‘at times’ is also called fiber optic isolator and polarization maintaining optical isolator. It allows and keeps light to travel in one direction only. Its prime job is to prevent back reflection and backscattering in the reverse direction, for all states of polarization. In technical terms, the device is a two-port micro-optic isolator built with PM panda fiber. The isolator is commonly used in lasers, fiber optic systems, and amplifier systems. It actually prevents feedback which is not at all required in an optical oscillator.

Some devices in which this isolator is used

PM isolator is utilized all over the world majorly in communication systems, instrumentation applications, and polarization maintaining fiber-optic amplifiers. The isolator is also used in fiber optic system testing and fiber-optic LAN system and CATV fiber optic links.

Some of the many great features of these isolators

High isolation capacity

High Extinction Ratio

High Return Loss

Low Insertion Loss

Every fiber optic isolator has an optical fiber inside of it which is the most important component. Let’s now discuss how it works.

Optical fiber inside such isolators is a thin strand made of pure glass. It acts as a guide for the light wave over long distances by following the principle of ‘total internal reflection’. These are very effective when the light waves try to pass between two varying media.

The fiber inside these devices including polarization maintaining optical isolator is composed of two layers of glass – the core and the cladding. The core typically carries the actual signal of light and the glass layer surrounding the core is called cladding. In comparison to the core, the cladding has a lower refractive index. All of this causes total internal reflection successfully within the core.

What is transmitted over fiber?

Most fibers work in pairs where digital signals are encoded in light’s analog pulses preferably via the NRZ modulation – Non-Return to Zero. Since they operate in pairs, one is used to transmit while the other to receive, however, both signals can also be sent over a single stand.

Basic yet most used fiber types

SMF – Single Mode Fiber

MMF – Multi-Mode Fiber

The actual difference basically lies in the size of the core. SMF has an in-depth narrow core not more than 9µm which allows the propagation to just a single mode of light, whereas, MMF has a greatly wider core somewhere around 50µm and 62.5µm is also available on the market. MMF allows multiple modes of light to propagate. They both have their different characteristics along with their own pros & cons.

The Role of Optical Fiber Splicing Machine

Fiber optics was a turning point in the field of telecommunication. It marked the era of new heights in the field of communication. With fiber optic cables being a ground-breaking innovation, the fusion splicing machine became the next improvement which improved networking and industrial communication to a great extent. The fusion splicing machines improves the performance and the efficiency of the optical fibers. In this post let us take a look at how a fusion splicing machine dictates the performance and the characteristics of fiber optic cable.

What is a fusion splicing machine?

The process of fusion splicing is aimed to fuse two ends of a cable and form a secure connection between two or more fibers sections and ensure that loss is minimal while the optical signal passes. In fusion splicing, two sections of fibers are melted together which can’t be replaced. The fusion splicing process is done with a machine called the fusion splicer. The machine precisely aligns, both ends of the fiber cable and fuses it by the production of an electric arc. Now let us see what role a splicing machine plays in improving the efficiency of fiber optics.

It extends the limitation of other systems

One of the greatest advantages of fiber optics is that it helps in overcoming the pitfalls of various systems such as Ethernet, RS-232, or 422/485. The optic fibers have the upper hand when it comes to long-distance and speed. This is because the fusion splicing machine can connect the fiber optic cables without any flaws or breaks and ensures seamless data transfer. If you want to provide robust data transfer to users then it is time to discuss the optical splicing machine price.

 Precise fusion

A fusion splicing machine that is well-built and powerful will not only work on standard fibers but it also works on extremely small plastic fibers. This versatility is what makes the fusion splicing machine a winner when it comes to improving the efficiency of fiber optic cables. Next comes precision, precision is an imperative factor to produce fiber optics with punctual light refraction and reflection ability. This has a great impact on the ability of the fiber to carry data signals. If you are aiming to buy a top-notch splicing machine that is versatile and precise then take a look at the Fujikura splicing machine price in Chinaas it has the latest V-groove technology.

Has an impact on the speed

Fiber optics is sought-after by many due to its speed in transmission of data. Only a fiber optic fusion splicing machine will produce such impeccable fibers that have extremely fast uploads and downloads. This machine also helps to attain what is called symmetric speed.

The loss of splicing is less

The loss of energy will be less only when the distance between the two ends is comparatively less. Advanced splicing machines which have integrated real fiber core visualization technology helps in keeping the loss minimal. In most of the machines, the optical loss aimed is less than 0.1TB.

 Bottom line

The fiber splicing machine price in China comes somewhere around the higher price point range. You might feel that it is costly but in reality, the machine will be an asset for you and your company as it will produce robust fibers and improve the business revenue. Without further delay invest in a splicing machine and achieve great heights.

Tips for Fusion Fiber Splicing

Whether you need to extend the reach of fiber or repair a severed cable in the field, fiber splicing is a critical skill for any field tech. Here are a few useful tips to ensure your splices are done safely and effectively.

NOTE: There are two methods of fiber splicing: fusion splicing and mechanical splicing. For the purposes of this article, we will specifically discuss fusion splicing. For mechanical splicing, only the actual splice is a different process; the preparation and safety tips apply to each method.

Required Tools

Fiber fusion splicing unit

Fiber cleaver

Wire stripper, for removing jacket and tubing

Heat shrink tubes to protect and cover the splice

Cleaning supplies, including gauze and alcohol

Important Tips

1. Control your environment. Only attempt the splicing process (stripping, cleaving, and splicing) on a stable flat surface. Try to control any moving air (wind or AC) to minimize the risk of losing dangerous fiber splinters. Most importantly, keep everything as clean as possible. Wipe the exposed ends of the fiber thoroughly with gauze and alcohol before cleaving, and make sure your surface area is free of all dust and debris. As is the case with fiber connectors, the smallest impurities can introduce significant loss.

2. Handle fiber with extreme care. Handling bare fiber is incredibly dangerous. Even microscopic splinters can cause serious damage if they enter your bloodstream. Use a reverse roll of tape to collect any bits of fiber until they can be disposed of safely.

3. Measure three times, cut once. Check every setting on every tool before use. Measure out the length of jacket you’ll strip from your fiber ends (Ensure the fiber type settings on your cleaver and splicer match the fibers you have. Check the alignment of your fiber holders. Run an arc test on your splicing device to ensure you have a good cleave. If applicable, make sure your heat shrink tube is on one end of your fiber before splicing.

4. Respect the tools. A good fusion splicer and cleaver can perform their required tasks with extreme precision and can cost thousands of dollars apiece. Therefore, to get the most out of your investment, perform regular maintenance on these devices as instructed in the manual.

Precise execution of fiber splicing is essential to preserve the integrity of your network.  To learn more about best practices in networking care, check out our three-part series on cleaning and maintenance of your optical transceivers and cables.

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 fiber 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?

Fiber Optic Cable to Test

Power Meter

Light Source

What Training Does an Installer Need?

A Power Meter and Light Source are a pretty simple piece of test equipment to use. 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?

• 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.