Why you should care about better fiber optics?
Doing some research online we found this article in the Fhys.org Website, The original article was delivered by the Norwegian University of Science and Technology.
Fiber optic research can give us better medical equipment, improved environmental monitoring, more media channels—and maybe better solar panels.
"Optical fibres are remarkably good at transmitting signals without much loss in the transfer," says Professor Ursula Gibson at NTNU's Department of Physics.
However: "Glass fibres are good up to a wavelength of about 3 microns. More than that, and they're not so good," she says.
And that is sometimes problematic. Telecom uses the near-infrared part of the wave spectrum because it has the least loss of energy when passing through the glass.
But if we could utilize even longer wavelengths, the benefits would include better medical diagnoses and more precise environmental monitoring of airborne gas particles. Longer wavelengths could also mean more space for media channels since the competition is fierce for the wavelengths where free space transmission normally takes place now.
Optical glass fibres are not made of pure glass, but require a core with a bit of some other material to transmit signals.
This is clearly quite complicated to achieve, and the methods have gradually been perfected over the last 50 years.At NTNU, various research groups have been experimenting with optical fibres using a semiconductor core of silicon (Si) and gallium antimonide (GaSb) instead of small amounts of germanium oxide, which is used in silica fibres now. Some of the researchers' latest research findings have now been presented in Nature Communications.
Ph.D. candidate Seunghan Song is the first author of the article in the prestigious journal. The article "describes a method for making optical fibers were part of the core that is gallium antimonide, which can emit infrared light. Then the fiber is laser treated to concentrate the antimonide," says Gibson.
This process is carried at room temperature. The laser processing affects the properties of the core.
Silicon is well known as the most commonly used material in solar panels. Along with oxygen, silicon is the most common material in glass and glass fiber cables as well.
Gallium antimonide is less typical, although others have also used the same composition in optical instruments. But not in the same way.
With the new method, the gallium antimonide is initially distributed throughout the silicon. This is a simpler and cheaper method than others to grow crystals, and the technology offers many possible applications.
"Our results are first and foremost a step towards opening up a larger portion of the electromagnetic wave spectrum for optical fiber transmission," Gibson says.
Learning about the fundamental properties of the semiconductor materials in glass fibers allows us to make more efficient use of rare resources like gallium.
New Fiber Optics transmission record reported at OFC2018
The NICT (Network System Research Institute )and Fujikura Ltd. (Fujikura, President: Masahiko Ito) developed a 3-mode optical fiber, capable of wide-band wavelength multiplexing transmission with a standard outer diameter (0.125 mm) that can be cabled with existing equipment.
The researchers have successfully demonstrated a transmission experiment over +1000 km with a data-rate of 159 Tb/s. Multimode fibers have different propagation delays between optical signals in different modes that make it difficult to simultaneously satisfy large data-rates and long-distance transmission. This achievement shows that such limitations may be overcome.
Converting the results to the product of data-rate and distance, which is a general indicator of transmission capability, results in 166 Pb/s×km. This is the world record in a standard outer diameter few-mode optical fiber and the largest data-rate over 1000 km for any kind of standard-diameter fiber. In order to achieve the transmission capacity of 159 Tb/s, mode multiplexing is used in combination with 16-QAM (quadrature amplitude modulation), which is a practical high-density multilevel modulation optical signal, for all 348 wavelengths and MIMO (multiple-input and multiple-output) enables unscrambling of mixed modal signals even after transmission over more than 1000 km. This shows that standard outer diameter multimode fibers can be used for communication of high capacity optical backbone transmission systems.
The results of this demonstration were selected for presentation as a post-deadline paper at the 41st Optical Fiber Communication Conference and Exhibition (OFC2018).
In order to cope with ever-increasing communication traffic, research on large-scale optical transmission using new types of optical fiber exceeding the limit of conventional optical fiber and its application is actively conducted all over the world. The main new types of optical fibers studied are multicore fibers in which multiple passages (cores) are arranged in an optical fiber and multimode fibers that support multiple propagation modes in a single core with a larger core diameter. Up to now, successful transmission experiments of large capacity and long distance have been reported for multicore fiber, but it was considered that transmission which satisfied both large capacity and long distance simultaneously was difficult in multimode fiber.
In this work, NICT constructed a transmission system using an optical fiber developed by Fujikura and successfully transmitted over 1045 km with a data-rate of 159 Tb/s (Fig. 1). Converting the results to the product of transmission data-rate and distance, which is a general indicator of transmission capability, is 166 Pb/s×km. This is about twice the world record so far in the few-mode fibers.
The transmission system consists of the following element technologies.
3-mode optical fiber with standard outer diameter 0.125 mm
348 wavelength optical comb light source
16-QAM multi-level modulation technology equivalent to 4 bits / single polarization symbol
Separation technology of multimode optical signals with different propagation speeds in fiber (MIMO processing)
The researchers succeeded in transmitting over 1045 km using a standard 3-mode optical fiber. When laying of standard outer diameter optical fibers takes place, the existing equipment can be used and the practical use at an early stage is promising. Also, the ultimate large-capacity transmission will become possible in the future if combined with multicore technology, which is researched by NICT in cooperation with industry, university, and government in Japan.
The researchers will continue to research and develop future optical communication infrastructure technologies which can smoothly accommodate traffic such as big data and 5G network services.
The recent state of Optical Fiber Connectors
We have already covered the fundamentals of the optics connectors in a previous post. We explained the differences in polishing, RL and IL and choosing the right one. Nonetheless, technology keeps moving forward, and we need to be aware of the latest advancements so we can properly take advantage of the resources at our disposal.
In this post, we’ll take a look at the most recent developments in the field of connectors. So feel free to join the ride, and explore what the next generation of connectors is all about!
Nowadays, physical space has become an important issue. With the advent of more connection needs, size has gotten increasingly valuable when it comes to adopting new connections for the future. This is where splice-on connectors come in handy since they have expanded the catalog of resources for companies that need to establish new connections in their plants.
New connectors, ranging from fiber-to-the-x (FTTx) to no-epoxy/no-polish (NENP), for example, are now being used to augment speed and diminishes expenses. These new modules allow to decrease the size required for a “splice tray” and diminish the cost of space needed. This shall be the trend followed by the new developments in optic fiber connectors.
The increasing demand for access networks and the increased value of rack space has originated the inclusion of small form connectors or multi-fiber connectors with high-bandwidth features. This need is represented by repair, need to improve fiber routing, fiber system upgrades and installation of space to temporary connections.
The current needs of the optic fiber scene have aimed towards a technology and equipment-cost perspective. The demand and the technology and have made a notorious impact on the cost and performance of the next generation of connectors.
The other area that has been dramatically changed in field termination, is represented by the need for an angled polished connector (APC) end face as the interface. APC interface has become the industry standard for FTTx and other outside plant equipment. That being said, the cost of material per termination has been reduced considerably as the new generation of connectors has become commonly utilized.
These connectors have been made by taking the existing field fiber and adhering it inside the ferrule. These anaerobic terminations are low-cost connectors that offer a robust performance over time and throughout changes in temperature. Anaerobic connectors have now been justifiably accepted in the optic fiber industry. Perhaps the only limitation of these terminations it that their efficiency is highly determined by the expertise of the technicians who install them and handle them.
No-epoxy no-polish (NENP):
These connectors posses a physical way of retaining the field fiber by compression and meet the fiber retention qualities while offering/providing a factory-polished end face for mating in the adapter. The only conditions for a proper performance of this type of terminations are represented by location and stability. The retention technology that these terminations offer is established by its manufacturers. The only foreseeable limitation is the impact of temperature in these terminations, which can cause unwanted margins of loss.
NENP angled polished connectors: The introduction of consistent APC terminations has filled the necessity of field-installed APC connectors in FTTx-type projects. However, the incorporation and alignment of these connectors are both time-consuming and extremely craft-sensitive. The consequence is a considerable need for a higher maintenance, which may add cost to the termination.
The variables of field deployment range from temperature change, performance variation due to factory fiber characteristics, quality of field fiber with regards to quality of fiber, tools and termination process. Taking into consideration all of these variables when defining a mechanical connector, the manufacturers have been able to consistently meet the insertion of loss requirements. The individual optical performance requirements have to be addressed with the specific mechanical connector manufacturer to guarantee a flawless optical plant is being put together.
Fusion splice-on connectors:
These connectors remove some variables and add strength. The vast majority of splice-on connectors are now available for use in the field and they are able to retain a consistent splice loss and return loss over temperature and time. These connectors can keep the performance of a splice-on pigtail without having to store a splice sleeve and they stand for being the most robust and consistent option for field-installable fiber connectors.
These terminations provide offers strength in numbers. Holding the strength from the fusion splice type connector and expanding its flexibility for field deployment generates a field-installable multi-fiber connector known as the MPO (multi-fiber push on). This connector offers the same benefits as a single fiber fusion splice-on connector but terminates up to 12 fibers per connection. This type of connector helps with restoration, repair and upgrade projects of existing MPO networks. The factory end face and fusion spliced optical path produce a solid alternative for field termination. The MPO termination has been growing and will continue to grow with fiber consolidation and high-speed bandwidth connections.
Self-contained patch and splice modules:
This is a variation of field-installable termination that goes into a self-contained field-installable patch and splice module. Field-installable modules employ a traditional pigtail splice to an adapter; fortunately, the need for factory pre-termination is removed. This is very convenient to those cases where space is limited or when you need a small footprint fiber termination. Because this module is self-contained, patch and splice, this option constitutes a cost-effective solution when adding a circuit to an existing fiber rack system or colocation type deployment.
Taking a decision towards which one of these options are the best for your needs is certainly not easy, but that doesn’t mean that you won’t be able to make a proper decision. You just need to gather a good amount of solid information based on what your system really needs.
It is mandatory then to have a good sense of the space available for potential adjustments. That being said, you then need to take a close look at the available options offered by trustworthy manufacturers. If you do a thorough research, rest assured that you will find the resources that will accommodate your needs.
So don’t despair if you suspect that you’re not able to find a perfect solution to your problem because more often than not, that seems to be the case. Just make sure to focus on having a solid understanding on the demands, study proficiently the resources at your disposal and then get prepared to make the ultimate decision that will help you satisfy what you most urgently need for.
We really hope you can find all of this information very useful for your projects.
News for Monday 15 July, 2019