Choosing the “Right” Optical Fiber – Single-Mode or Multimode?

A huge increase in digital devices, cloud computing and web services have helped fuel the tremendous demand for increased bandwidth while also pushing datacom rates to 100G and beyond. With these faster speeds and greater use, system designers might assume that single-mode optical fiber holds a growing advantage over multimode optical fiber for premises applications. However, it’s critical to remember that increased Ethernet speeds don’t necessarily mean that single-mode fiber is the best choice.

While it’s true that single-mode fiber holds bandwidth and reach advantages, especially for longer distances, multimode fiber easily supports most distances needed by data center and enterprise networks, and at a significant cost savings over single-mode fiber.

What’s the Difference?

These two optical fiber types were primarily named for the different ways that they transmit light. Single-Mode optical fibers have a small core size (less than 10 microns) and allow only one mode or ray of light to be transmitted. These fibers were mainly designed for networks that involve medium to long distances, such as metro, access and long-haul networks.

On the other hand, multimode fibers have larger cores that work to guide many modes at the same time. These larger cores make it much easier to capture light from a transceiver, helping to control source costs.


View our Single Mode vs. Multimode Fiber Guide

WHICH Multimode Fiber?

Today, network designers and end users can choose from OM3, OM4 or OM5 grades of 50 micron multimode fibers. At one time in the 1980s, as data rates increased, 62.5 micron fiber was introduced because it allowed for longer reach to support campus applications. However, with the advent of gigabit speeds, users moved back to 50 micron fiber with its inherently higher bandwidth. Now 50 micron laser-optimized multimode OM3, OM4 and OM5 fibers offer major bandwidth and reach advantages for short-reach applications along with low system costs.

The Future

Industry standards groups such as IEEE (Ethernet), TIA, ISO/IEC and others continue to recognize multimode optical fiber as the short-reach solution for next-generation speeds. In fact, TIA issued a new standard for the next generation of multimode fiber called wide band (OM5) multimode fiber. This new version of 50 micron fiber can transmit multiple wavelengths using Short Wavelength Division Multiplexing (SWDM) technology, while maintaining OM4 backward compatibility. This capability lets end users gain greater bandwidth and higher speeds from a single fiber by simply adding wavelengths. The OFS version of this fiber is LaserWave® WideBand (OM5) Optical Fiber.

In Short…

Generally, 50 micron optical fiber continues to be the most cost-effective choice for enterprise and data center use up to the 500-600 meter range. Beyond that distance, single-mode optical fiber is necessary.

The OFS LaserWave FLEX Multimode Optical Fiber family offers full performance range and has better optical and geometric specifications than standards require. However, if the network’s transmission distance requires the use of single-mode optical fiber, consider bend-insensitive, zero water peak (ZWP) full-spectrum fibers such as the OFS family of AllWave® Optical Fibers.

Breaking the Transatlantic Record

Making an overseas phone call? Using cloud computing? If so, there’s a 99 percent chance your call or message is being carried by an undersea fiber optic cable.

 

Now, new research with lasers may let service providers “push” even more data through these cables to help meet the booming demand for transmission between North America and Europe. In fact, this new method could even increase network capacity without requiring new ocean cables, which can cost hundreds of millions of dollars to manufacture and install.

 

Setting A New Standard

A research team from Infinera has set a new efficiency standard for transatlantic fiber optic cables. Testing 16QAM modulation – a new approach to transmitting light signals — the group not only shattered efficiency records for data transfer. They nearly doubled data capacity and approached the assumed upper limit for this type of transmission.

 

The team managed to extend record-setting capacity across the Atlantic Ocean  using the MAREA transatlantic cable. This cable spans approximately 4,104 miles (6,605 kilometers) from Virginia Beach, Virginia, to Bilbao, Spain. Partially funded by Facebook and Microsoft, MAREA now holds the record for the highest-capacity cable crossing the Atlantic Ocean.

 

Skyrocketing Demand

The need for new and better optical fiber and fiber optic cables has constantly grown since the first undersea trans-Atlantic cable was installed back in 1858.  Because of the move to cloud-based computing, that demand has skyrocketed over the past decade.

 

It’s important to note that while this was the first time that PM-16QAM signals were sent over this distance, the team combined equipment readily available to the industry with high-speed lasers to make the transmission. The team generated signal speeds reaching 26.2 terabits per second, a 20 percent increase over what cable developers believed was possible.

 

Even More Good News

This experiment delivered results much the same as next-generation chip sets from other vendors that use a different technique called probabilistic constellation shaping (PCS). According to the research team, the good news for service providers is that the new technique can be combined with PCS for even faster speeds in the future.

 

The group presented their research results at OFC 2019 in San Diego.

New Ways to Twist and Shift Light

The National Physical Laboratory (NPL) recently conducted photonics research that may lead to new quantum technologies and telecom systems. The researchers discovered unexpected qualities in light that could, in the long term, lead to completely new electronic devices and applications.

Light is frequently used in electronics involved in telecommunications and computing. One good example of this is how light is used in optical fiber. Optical fiber and fiber optic cables are used to transmit many types of communication around the world, including telephone calls and internet connections.

As mentioned in Physical Review Letters, the NPL researchers studied whether and how light can be controlled in an optical ring resonator. This resonator is a tiny device that can store extremely high light intensities. In an optical ring resonator, wavelengths of light resonate around the device. A comparison would be how some “whispers” can travel around a  “whispering gallery” and be heard on the other side.

In a first-ever study, the researchers used optical ring resonators to pinpoint the interaction of two kinds of spontaneous symmetry breaking. The team displayed new ways to manipulate light by (1) studying how time varied between pulses of light and (2) how the light was polarized.

Typically, light follows what is called “time reversal symmetry.” This principle means that if time is reversed, light should return to where it started. However, in the NPL research, at high light intensities, symmetry was broken within the optical ring resonators. A lead scientist on the project noted that, when the ring resonator was seeded with short pulses, the circulating pulses inside the resonator would arrive either before or after the seed pulse. However, they would never arrive at the same time. This discovery could be potentially used to combine and rearrange optical pulses in telecommunications networks.

The researchers also learned that light can suddenly change its polarization in ring resonators. A related example would be you picking a guitar string in a vertical direction, but then having the string begin to vibrate in either a circular clockwise or counter-clockwise direction. The researchers believe that the results of these experiments will not only help to direct the development of improved optical ring resonators (such as for atomic clocks for exact time-keeping). They also feel that these findings will also help scientists to understand how they can control light in photonic circuits in sensors and in quantum technologies.

According to Pascal Del’Haye, NPL Senior Research Scientist, “Optics have become an important part of telecom networks and computing systems. Understanding how we can manipulate light in photonic circuits will help to unlock a whole host of new technologies. These include better sensors and new quantum capabilities, which will become ever more important in our everyday lives.”

Lighting Up Dark Fiber

Last month, internet speeds in Jackson, Mississippi, jumped from 1 Gb to 100 Gb. This leap forward is part of the city’s work to light up “dark fiber” in the robust fiber optic network that it owns.

The Origin of Dark Fiber

The term “dark fiber” refers to unused or underused fiber optic infrastructure (optical fibers, fiber cables and repeaters). Because it’s expensive to deploy cable (especially under oceans), companies typically install more fiber than they will need. This fact was especially true during the dot.com boom of the 1990s. However, after the bust of the early 2000s, many companies either went bankrupt or merged. The result is that today, in addition to “lit fibers” (fibers currently transmitting data by light), there are many “dark fibers” (unused fibers) within the same networks.


Cities Lighting UpBecause it’s possible to buy or lease these fibers, some cities and companies see using dark fiber as an appealing way to save money or create a new revenue stream. However, there are other factors to consider because using dark fiber isn’t straightforward. Buying and managing a fiber network takes skills that many organizations simply don’t have. Also, when a group starts selling network bandwidth, it takes on the role of becoming an ISP.

And on top of this, success isn’t always guaranteed. Take the example of California’s Santa Monica CityNet. In 2014, CityNet became the first 100 gigabit municipal network in the country. However, in its efforts to lease dark fiber, CityNet has signed up less than 2 percent of the business market since 2006. It has also collected only about $2.1 million in revenue over that time.

Other Uses

At least for now, dark fiber still has staying power. One factor driving its use is cloud computing which requires greater bandwidth. However, dark fiber could face greater competition as cities get “smarter” and 5G wireless communications roll out.

Ironically, dark fiber’s strength may come through uses besides connectivity. At the Lawrence Berkeley National Laboratory, Dr. Jonathan Ajo-Franklin is using dark fiber to measure seismic signals. Dr. Ajo-Franklin’s team gained permission to access a section of a dark fiber network between Sacramento and Calusa, California. During a seven-month experiment, the team collected about 300 terabytes of data. Ultimately, they found that the same dark fiber installed for communications was also useful in making distributed measurements. These measurements included seismic wave fields, temperature, strain and vibrations that can affect infrastructure (such as the number of cars on a road). In other words, an unused fiber installed for a telecom network might also be used in sensing.

What’s more, by using dark fiber, the team saved a substantial amount of money by replacing a critical, huge array of thousands of individual point sensors with an existing, installed fiber optic cable.

Fiber to the Home Growth Keeps Exploding

Smart Home App ConnectivityThe growth in Fiber to the Home (FTTH) just keeps exploding. In fact, for the first time ever, optical fiber passed DSL in home usage during 2018. Fiber is now the second most-frequent connection for North American home Internet.

And FTTH is also the second most-often-used, fixed broadband connection medium in North America. A newly-issued report from the Fiber Broadband Association (FBA) and RVA, LLC featured these statistics.

Fiber Passes xDSL

As of September 2018, the report found that all-fiber access networks surpassed xDSL connections. Almost 60 million homes were FTTH service capable and 23.8 million homes were already connected. These totals represent an increase of 22% from 2017 in terms of “homes marketed.” According to RVA, “homes marketed” depicts market potential more meaningfully than “homes passed” by fiber.

Unsurprisingly, 40.8 million of these homes are in the United States. Another 5.6 million homes are in Canada, 13.1 million in Mexico and 350,000 in the Caribbean.

In terms of the United States, new homes marketed hit a record high of 5.9 million in 2018. Of the 40.8 million homes marketed, the report calls 39.2 million “unique.” This term refers to homes that do not have more than one all-fiber operator seeking their business. Overall. FTTH connects 18.4 million homes in the U.S. Tier 1 telco operators account for 72.6% of these connections. Tier 2 and 3 operators handle 10.3%, and cable operators account for 5.5% of U.S. FTTH connections.

Canada Picks up the Pace

Canadian operators may be rolling out optical fiber faster than U.S. companies, at least in terms of homes marketed compared to total homes. However, FTTH still has a way to go to threaten hybrid fiber/coax (HFC). HFC still delivers slightly more than 50% of broadband connections in North America and FTTH provides not quite 25%.

Fiber is on Fire

According to Lisa R. Youngers, president and CEO of FBA, “The fiber industry is on fire. Fiber holds the key for next-generation connectivity, from 5G to smart cities to the Internet of Things (IOT). This research and analysis helps keep the industry, consumers and policymakers informed about FBA’s progress toward a better-connected future.”

The “Wet Net” World of Underwater Fiber Optic Cables

You panic when even a few drops of water fall on your laptop. Everyone knows that water and electronics don’t “mix.” That’s why it seems so ironic that most of the Internet’s “hard” infrastructure lies underwater on the ocean floor.

Virtually all global data travels through millions of miles of submarine fiber optic cables beneath the ocean’s surface. More than 350 subsea cable lines stretch from the U.S. West Coast to the East Coast, with many more being deployed to connect countries around the world.

Installing submarine fiber optic cables deep on the ocean floor is time consuming and expensive. While special ships deploy the cable, ocean divers repair and maintain the network. And even with thick, protective jackets, there are many ways to damage a cable. Some destructive forces include ship anchors, commercial fishing equipment, earthquakes, hurricanes and even sinister interference. (more…)

5G: What’s All the Hoopla About?

5g and Fiber Optics There’s been lots of excitement and even some “hype” around the idea of 5G. But what is it really? Does it mean just faster internet? Will it really be that much better than 4G? Many people are asking these questions as the FCC begins to auction the first licenses for the airwaves that will carry 5G service.

 

What Is 5G, Really?

5G will be up to 100 times faster than today’s cellular connections – and even faster than many home fiber optic broadband services. But it’s not just about speed. Networks will have greater capacity and respond faster than earlier wireless services. More people and devices will work at the same time on the same network without slowing it to a crawl. And it will do all of this with lower latency. Latency is the time delay between a device contacting the network and receiving a response.

This improved latency will help to bring about some of the most amazing tech trends on the horizon. And while 5G may not change your life right away, it will certainly bring some totally new technologies to life. For now, here are a few of the most exciting apps and technologies that 5G will enable.

Promising 5G Applications

Self-driving vehicles – Self-driving cars will be a common sight with the next generation of wireless service.  And 5G will make vehicle-to-vehicle communication happen – where cars can almost instantly share information between them on their location, speed, acceleration, direction and steering. Many experts believe that this feature will become the greatest lifesaving advance in the auto industry in more than a decade. Using this, cars will know before their drivers when another car moves into your blind spot or when a dump truck that’s six vehicles ahead suddenly stops.

Telesurgery – Remote surgery isn’t new. However, 5G could make a huge difference in providing medical care to millions in distant locations, along with training doctors remotely in surgery and other specialties.

Virtual Reality – For truly realistic virtual reality (VR), a wireless network must carry tons of data. And while it must be fast, the network must also handle this data deluge to create a life-like VR experience. It will take 5G to make this happen.

Drones: 5G technology will let drones talk to one another, helping prevent overhead accidents while in flight.

5G wireless networks can make many of the technologies, applications and experiences that we’ve been waiting for a reality.

Can a Quantum Network “Hacker Proof” Fiber Optic Cables?

Hack Proof Fiber Optic Cable

In 2013, Edward Snowden, a U.S. National Security Agency contractor, leaked documents showing that intelligence agencies were spying on the data of private citizens. One disturbing fact was that the spies tapped into optical fiber cables to access the huge amount of data moving through these cables.

Snowden’s disclosures pushed researchers to use quantum science to make this type of hacking impossible. Finally, there are reports of progress.

THE QUANTUM KEY DISTRIBUTION APPROACH

A startup called Quantum Xchange will access 500 miles of optical cable along the Eastern U.S. coast. Quantum will use this cable to create the country’s first quantum key distribution (QKD) network.

Quantum Xchange’s “QKD approach” would send an encoded message in bits while transmitting the decoding keys as quantum bits, or qubits. Usually in the form of photons, the qubits travel easily along fiber cables. However, any attempt to spy on a qubit would instantly destroy its fragile quantum state, erase any data and leave the mark of an intrusion.

One possible issue is that “trusted nodes” must be used to send quantum keys over long distances. These nodes act as repeaters to boost signals in a typical data cable. Quantum Xchange plans to have 13 trusted nodes along its entire network. At these node points, keys are first turned into bits. Then, they are changed back to a quantum state to be sent on. In other words, a hacker could theoretically steal these bits as they are momentarily vulnerable.

AN ALTERNATE METHOD: QUANTUM TELEPORTATION

Along with this news, the University of Chicago, the Fermi National Accelerator Laboratory and Argonne National Laboratory will jointly develop a test bed to use quantum teleportation to create secure data transmission.

Quantum teleportation would use entanglement to eliminate the risk of hacking. Entanglement creates a pair of qubits (usually photons) in a single quantum state. A change in one photon instantly affects the linked photon, even if they are far apart. Therefore, in theory, it should be impossible to hack data transmission using entanglement. This is so because tampering with one of the qubits would destroy both quantum states.

However, the entanglement method is still confined to research labs. And there are huge challenges to making this approach work in the real world. According to Dr. David Awschalom of the University of Chicago, creating and maintaining entanglement would be extremely difficult over a long haul fiber optic network.

Dr. Awschalom is leading the project involving the university and the national labs. The goal is to have the test bed use a “plug-and-play” approach that will let the researchers experiment and evaluate different techniques for entangling and transmitting qubits.

The U.S. Department of Energy will provide several million dollars to fund the test bed. This test bed will use a 30-mile stretch of installed optical cable between the labs. Members of the Chicago Quantum Exchange will operate the test bed and project. This Exchange consists of 70 scientists and engineers from the three organizations.

Could “Twisted” Fiber Optics Create a 100 Times Faster Internet?

Optical Fiber EndsResearchers at Australia’s RMIT University recently discovered a new fiber optic breakthrough that could lead to 100 times faster internet speeds. This new development detects light that has been twisted into a spiral.

According to research in Nature Communications, developers could upgrade existing fiber optic networks and boost efficiency using this discovery.

HOW IT WORKS

Fiber optic cables use pulses of light to transmit information. However, users can only store that data based on the color of the light and whether the light wave is horizontal or vertical.

The RMIT researchers twisted light into a spiral and created a third dimension for light to carry information – the level of orbital angular momentum, or spin. Dr. Min Gu of RMIT compared it to the double helix spiral of DNA. According to Dr. Gu,  a greater amount of angular momentum allows an optical fiber to carry a larger amount of information.

Researchers have used “twisted light” approaches and orbital angular momentum before. They encoded a greater amount of data in various degrees of twist using these “twisted” methods. In fact, researchers at Boston University and the University of Southern California developed an optic fiber that could twist light. However, the teams used detectors as large as “the size of a dining table.” The RMIT researchers created a reasonably-sized detector that reads the information it holds. The new detector is the width of a human hair.

WHAT IT CAN DO

Providers could upgrade long haul networks around the globe with this new fiber optic technology. These companies include the NBN Co. NBN is deploying Australia’s national broadband network. The company expects to complete this network by 2020.

NBN is “prepared for future demand.” However, they have also stated that fiber optic advances such as this one by RMIT need further testing and acceptance before being deployed. A spokesperson commented, “Laboratories continually test new communications technologies for many years before they are commercialized. Equipment manufacturers and network operators must accept these new methods on a widespread scale before they are ready to be deployed in the field.”

Melting Arctic Ice Could Mean Faster Internet for Some

Have you ever wondered how an e-mail reaches your inbox from a co-worker in Europe? Or how a Facebook message gets to you from a cousin in Africa?

The answer lies beneath the ocean. More than 745,000 miles of submarine cables featuring optical fiber make up most of the actual physical internet. These cables wind between and around continents, carrying almost all of our global internet communication.

Recently, the huge amount of data sent between connected smart devices has begun clogging this network of submarine cables, just as interstate highways become jammed with traffic. One way to deal with this massive data growth is to increase the bandwidth capacity of the physical internet. Another way is to create more direct transmission paths between continents.

Taking It Direct

A new project in Finland hopes to use this second method. The plan is to install a new fiber optic cable route across the Arctic Ocean – the only large water body that is really untouched by submarine cables. While melting sea ice raises tremendous concerns for the health of our planet, it presents an entirely new opportunity to install digital links on a straight course between continents.

For data from Asia to reach Europe, it must travel over thousands of cable miles around Asia, up through the Suez Canal and across the Mediterranean Sea into continental Europe. And while this occurs faster than the blink of an eye (about 253 milliseconds), researchers say that data and communication could travel 30 percent faster over a shorter, more direct cable route through the Arctic.

Faster Connections Are Key

Banks and financial trading groups eagerly await faster connections. Traders depend on powerful, low latency networks to buy and sell securities where milliseconds can affect profit and loss. However, big data would also benefit. Today, internet-connected devices outnumber people on the Earth by an almost 3 to 1 margin. And experts predict that internet traffic between Europe and Asia will triple in the next five years.

 The Challenges

The deployment of this new cable would actually extend an existing cable route through Finland into Germany. And while a feasibility study by the Government of Finland calls the project a “win-win-win” for Europe, Russia and Asia, there are key areas of concern.

First, constructing this new cable route would cost nearly a billion Euros. Secondly, the icy Arctic terrain and harsh weather conditions would certainly present logistical challenges. And there are always issues involving security. However, a separate cable installation linking Tokyo and London by way of Alaska and Canada is already underway.

Our planet needs more almost supersonic connections. We can expect to see more efforts around the globe to reduce data “pile-ups” and speed the delivery of data and communication.