Three Critical Focuses on OM5 Fiber Optic Cable

by Fiber-MART.COM

As data centers scale to ever larger sizes in recent years, the demand for great bandwidth and higher speed is growing too. Recently, OM5 has been approved to be a new type of multimode fiber (MMF) for high speed data center applications. And various discussions about its characteristics and features attract much attention. This article will illustrate three important points that get the most concerns to help you get a clear view on OM5 fiber cable.

 

Basic Information About OM5 Fiber

OM5, known as wideband multimode fiber (WBMMF) earlier, is a newly standardized fiber cable by TIA and IEC. OM5 is a 50/125µm laser optimized multimode fiber with bandwidth characteristics specified for WDM (Wavelength Division Multiplexing). Compared with OM3 and OM4 which support a single wavelength of 850nm, OM5 is designed to support multiple relatively short wavelengths between 850nm and 953nm that can be aggregated for higher bandwidth applications. Moreover, in February 2017, TIA has approved lime green as identifying color for OM5 fiber optic cable. And the standard multimode fiber connector and adapters for OM3 and OM4 will still work with OM5 fibers. The only difference is that the color of connector and adapter housing or boot needs to be changed for easy identifications of OM5 connections.

 

Though OM5 shares the same fiber core size with OM3 and OM4, which makes it fully compatible with these types of fibers. That means the OM5 is able to be used in existing multimode fiber applications and supports future speeds when multi-wavelength devices become available.

 

Three Critical Focuses on OM5 Fiber

OM5 Vs. OM4 Vs. OM3: What Are the Differences?

As mentioned above, OM5 supports applications that using OM3 and OM4 fiber. But there are still differences between them. Here is a simple comparison among OM5, OM4 and OM3.

 

Jacket color. Generally speaking, the color of standard OM3 and OM4 fiber is aqua. While OM5 fiber is lime green.

 

Transmitting wavelengths number. OM5 can support at least four short WDM channels at a minimum speed through 850nm-953nm, which makes it different from OM3 and OM4 fiber that only support one wavelength at a time.

 

Maximum distance and working wavelength. As we all known, the usual working wavelengths of OM3 and OM4 are 850nm and 1310nm. But OM5 supports wavelengths between 850nm and 953nm. In same wavelength windows, the maximum distance of these three MMFs is different.

 

OM5 Vs. Single Mode Fiber in Data Centers: Which to Choose?

Although the price of single mode fiber (SMF) is reducing recently due to new technologies application, the cost of pluggable optics still limits the implementation of SMF in data centers. Compared to that, OM5 can multiplex four wavelengths spaced in the range of 850nm to 953nm, increasing data capacity by a factor of four as well as reducing fiber cost. Furthermore, MMF has more advantages on installation, troubleshooting, cleaning and overall maintenance, which makes it a better choice in data centers. However, the problem for MMF is distance. And the maximum distance will decrease as the data speed grows. Therefore, multimode fiber has higher value to network owners for distance up to 500m and OM5 allows for migration to 400Gbps at the distance up to 150m. For applications beyond 500m, single mode fiber should be chosen.

 

Is OM5 Compatible With Existing Optical Transceiver?

At present, OM5 fiber does not support existing optical transceiver. However, in a recent trade show, Finisar and Lumentum present an interoperability of 100G SWDM4 which is a new type of optical transceiver used with OM5. The SWDM4 transceiver uses a complex short wavelength division multiplex (SWDM) technology. Signals at four wavelengths (850nm, 880nm, 910nm and 940nm) are transmitted over one fiber. And only two fibers are required for bidirectional transmission. But this transmission also has limitation—it only suits for 100G to 100G direct connections, which is similar to the application of 100G CWDM4.

 

Conclusion

OM5 fiber, as a newly type of multimode fiber optic cable, has gained much attention among various optical vendors and manufacturers. It’s not denied that OM5 fiber will offer completely changes for data centers. But there is still a long way to go.

The transmission distance of our fiber optic transceivers ups to 120km

http://www.fiber-mart.com/fiber-optic-transceivers-xfp-transceivers-c-1_83.htmlAccording to the forecasts of Infonetics, the 100G optical transceiver sales will be doubled in the next two years; and the outlook of many other high-speed modules will be good too.But the QSFP+ enterprise applications are also in good uphill stages. Infonetics expected that the shipment of the 40G QSFP+ long-distance devices will be increased two times in 2017.

 

At the same time, along with intensifies of the 100G coherent deployment in China and other regions, the 40G coherent optical modules overall market is slipping, expect Japan.

The 2017 global optical transceiver market is healthy overall, increased by 10% to 16.3 hundred million dollars. For the 100G optical module, the tunable XFP optical module is the biggest winner, whose shipments are more than one time.

 

However, these devices also declined in price. Infonetics expects, tunable XFPs will continue to expand the future. Benefit from the continuous strength of 10G Metro markets, the unit shipments of tunable XFP optical modules in 2012-2017 CAGR are 36%.

 

In the general application, the requirement of understanding fiber optic transceiver includes the models, interface types, application fields except the internal structure of the optical module.

 

 In the fiber optical communication, the fiber optic transceiver contains the PON module (GEPON module and GPON module), SFP transceiver, SFF transceiver, 10G SFP+ Module, 10G XFP Module, GBIC Transceiver, RJ45 copper module, 1x9 duplex SC/ST connector fiber optic transceiver and so on. The range of the transmission data rate covers from the 100/125/155/622Mbp to the 1.062G/1.25G/2.125G/2.488Gbps. And the transmission distance ups to 120km.

 

As a professional fiber optical transceiver manufacturer and supplier, we supply all these fiber optic transceivers. For other information about our products, please visit our website.

---

something about optic fiber Splicing

A splice is a device to connect one fiber optic cable to another permanently. It is the attribute of permanence that distinguishes a splice from connectors. Nonetheless, some vendors offer splices that can be disconnected that are not permanent so that they can be disconnected for repairs or rearrangements. The terminology can get confusing.

Fiber optic cables may have to be spliced together for any of a number of reasons. 

One reason is to realize a link of a particular length. The network installer may have in his inventory several fiber optic cables but, none long enough to satisfy the required link length. This may easily arise since cable manufacturers offer cables in limited lengths - usually 1 to 6 km. If a link of 10 km has to be installed this can be done by splicing several together. The installer may then satisfy the distance requirement and not have to buy a new fiber optic cable.

Splices may be required at building entrances, wiring closets, couplers and literally any intermediary point between Transmitter and Receiver. 

At first glance you may think that splicing two fiber optic cables together is like connecting two wires. To the contrary, the requirements for a fiber-optic connection and a wire connection are very different. 

Two copper connectors can be joined by solder or by connectors that have been crimped or soldered to the wires. The purpose is to create an intimate contact between the mated halves in order to have a low resistance path across a junction. On the other hand, connecting two fiber optic cables requires precise alignment of the mated fiber cores or spots in a single-mode fiber optic cable. This is demanded so that nearly all of the light is coupled from one fiber optic cable across a junction to the other fiber optic cable. Actual contact between the fiber optic cables is not even mandatory. The need for precise alignment creates a challenge to a designer of a splice.

There are two principal types of splices: fusion and mechanical.

Fusion splices - uses an electric arc to weld two fiber optic cables together. The splices offer sophisticated, computer controlled alignment of fiber optic cables to achieve losses as low as 0.05 dB. This comes at a high cost.

Mechanical-splices all share common elements. They are easily applied in the field, require little or no tooling and offer losses of about 0.2 dB.

BASIC CABLE DESIGN

1 - Two basic cable designs are:

 

Loose-tube cable, used in the majority of outside-plant installations in North America, and tight-buffered cable, primarily used inside buildings.

 

The modular design of loose-tube cables typically holds up to 12 fibers per buffer tube with a maximum per cable fiber count of more than 200 fibers. Loose-tube cables can be all-dielectric or optionally armored. The modular buffer-tube design permits easy drop-off of groups of fibers at intermediate points, without interfering with other protected buffer tubes being routed to other locations. The loose-tube design also helps in the identification and administration of fibers in the system.

 

Single-fiber tight-buffered cables are used as pigtails, patch cords and jumpers to terminate loose-tube cables directly into opto-electronic transmitters, receivers and other active and passive components.

 

Multi-fiber tight-buffered cables also are available and are used primarily for alternative routing and handling flexibility and ease within buildings.

 

2 - Loose-Tube Cable

 

In a loose-tube cable design, color-coded plastic buffer tubes house and protect optical fibers. A gel filling compound impedes water penetration. Excess fiber length (relative to buffer tube length) insulates fibers from stresses of installation and environmental loading. Buffer tubes are stranded around a dielectric or steel central member, which serves as an anti-buckling element.

 

The cable core, typically uses aramid yarn, as the primary tensile strength member. The outer polyethylene jacket is extruded over the core. If armoring is required, a corrugated steel tape is formed around a single jacketed cable with an additional jacket extruded over the armor.

 

Loose-tube cables typically are used for outside-plant installation in aerial, duct and direct-buried applications.

 

 

3 - Tight-Buffered Cable

 

With tight-buffered cable designs, the buffering material is in direct contact with the fiber. This design is suited for "jumper cables" which connect outside plant cables to terminal equipment, and also for linking various devices in a premises network.

 

Multi-fiber, tight-buffered cables often are used for intra-building, risers, general building and plenum applications.

 

The tight-buffered design provides a rugged cable structure to protect individual fibers during handling, routing and connectorization. Yarn strength members keep the tensile load away from the fiber.

 

As with loose-tube cables, optical specifications for tight-buffered cables also should include the maximum performance of all fibers over the operating temperature range and life of the cable. Averages should not be acceptable.

Fiber Optic Cable are usually used in two scenarios

Fiber Optic Cable are used in applications where the optical signal is too strong and needs to be reduced. For example, in a multi-wavelength fiber optic system, you need to equalize the optical channel strength so that all the channels have similar power levels. This means to reduce stronger channels’ powers to match lower power channels.

The attenuation level is fixed at 5 dB, which means it reduces the optical power by 5dB. This attenuator has a short piece of fiber with metal ion doping that provides the specified attenuation.

There are many different mechanisms to reduce the optical power, this picture shows another mechanism used in one type of variable attenuator. Here variable means the attenuation level can be adjusted, for example, it could be from 1 dB up to 20dB.

Fiber Optic Cable are usually used in two scenarios.

The first case is in fiber optic power level testing. Cable are used to temporarily add a calibrated amount of signal loss in order to test the power level margins in a fiber optic communication system.

In the second case, Cable are permanently installed in a fiber optic communication link to properly match transmitter and receiver optical signal levels.

Optical Cable are typically classified as fixed or variable Cable.

Fixed Cable have a fixed optical power reduction number, such as 1dB, 5dB, 10dB, etc.

Variable Cable’ attenuation level can be adjusted, such as from 0.5 dB to 20dB, or even 50dB. Some variable Cable have very fine resolution, such as 0.1dB, or even 0.01dB.

This slide shows many different optical attenuator designs.

The female to female fixed Cable work like a regular adapter. But instead of minimizing insertion loss, it purposely adds some attenuation.

The female to female variable Cable are adjustable by turning a nut in the middle. The nut adjusts the air gap in the middle to achieve different attenuation levels.

The male to female fixed Cable work as fiber connectors, you can just plug in your existing fiber connector to its female side.

The in-line patch cable type variable Cable work as regular patch cables, but your can adjust its attenuation level by turning the screw.

For precise testing purposes, engineers have also designed instrument type variable Cable. These instrument type Cable have high attenuation ranges, such as from 0.5 dB to 70dB. They also have very fine resolution, such as 0.01dB. This is critical for accurate testing.

PON – Passive Optical Networks / Passive optische Netze

PON – Passive Optical Networks / Passive optische Netze

by Fiber-MART.COM

Ein passives optisches Netz ist ein Glasfasernetz, welches zur Signalverteilung ohne aktive Komponenten auskommt. Es arbeitet mit optischen Splittern, die über keine elektrischen Vermittlungsfunktionen verfügen. Passive optische Netze sind im Bereich zwischen Vermittlungsstelle und Teilnehmeranschluss für Gigabit-Glasfaseranschlüsse installiert. Sie funktionieren als Zugangsnetze für die Teilnehmer zum weltweiten Daten- und Kommunikationsnetz.

Man unterscheidet zwischen passiven optischen Netzen, die auf einer Punkt-zu-Punkt-Architektur und einer Punkt-zu-Mehrpunkt-Architektur basieren.

Die Abkürzung PON für Passive Optical Networks (Passive optische Netze) hat sich als Synonym für PtMP-Topologien entwickelt, obwohl z. B. PtP-Ethernet auch ein passives optisches Netz ist. Das heißt, wenn von PON die Rede ist, dann ist damit ein passives optisches Netz mit PtMP-Topologie gemeint.

PtP – Point-to-Point

Bei einer Punkt-zu-Punkt-Architektur hat jeder Teilnehmer von der Vermittlungsstelle (OLT) aus gesehen seine eigene Glasfaser, die bei ihm in der Wohnung oder im Einfamilienhaus endet. Weil für jeden Teilnehmer eine eigene Glasfaser verlegt ist, lässt sich Leitung und Dienst für jeden Teilnehmer entbündeln. Somit ist eine PtP-Topologie technologieunabhängig. Jeder Teilnehmer kann auf seiner Glasfaser einen anderen Anbieter wählen und der seine eigene Technologie. Auch ein späteres Aufrüsten gestaltet sich einfach. Mit PtP können die Anbieter flexibler auf die Bedarfsentwicklung der Kunden reagieren.

Ein Nachteil ist die hohe Anzahl an Ports in den Netzknoten. Denn jeder Teilnehmer hat seine eigene Glasfaser, die gespeist werden muss. Dafür braucht man Platz im Splitter und auch inder Vermittlungsstelle (OLT).

PtMP – Point-to-Multipoint

Bei einer Punkt-zu-Mehrpunkt-Architektur hat jeder Teilnehmer seine eigene Glasfaser, aber nur bis zum nächsten Kabelverzweiger. Dort befindet sich ein passiver optischer Splitter, der das Signal von einer Glasfaser aus der Vermittlungsstelle (OLT), auf alle Teilnehmerglasfasern aufteilt. Der Vorteil, für PON (PtMP) braucht man weniger Ports in der Vermittlungsstelle und damit weniger Platz- und Energiebedarf für Switches. In einem PON-Netz ist dafür das Entbündeln von Leitung und Dienst schwieriger, weil sich hier mehrere Teilnehmer eine Leitung teilen. Auch die Einführung einer neuen Technologie ist schwierig, weil sie für mehrere Teilnehmer auf einen Rutsch erfolgen muss.

Introduction à la fibre optique

Introduction à la fibre optique

by Fiber-MART.COM

Une fibre optique est un fil en verre ou en plastique très fin qui a la propriété d’être un conducteur de lumière et sert dans la transmission de données par la lumière. Elle offre un débit d’information nettement supérieur à celui des câbles coaxiaux et peut servir de support à un réseau « large bande » par lequel transitent aussi bien la télévision, le téléphone, la visioconférence ou les données informatiques. Le principe de la fibre optique a été développé au cours des années 1970 dans les laboratoires de l’entreprise américaine Corning Glass Works (actuelle Corning Incorporated).

Entourée d’une gaine protectrice, la fibre optique peut être utilisée pour conduire de la lumière entre deux lieux distants de plusieurs centaines, voire milliers, de kilomètres. Le signal lumineux codé par une variation d’intensité est capable de transmettre une grande quantité d’information. En permettant les communications à très longue distance et à des débits jusqu’alors impossibles, les fibres optiques ont constitué l’un des éléments clés de la révolution des télécommunications. Ses propriétés sont également exploitées dans le domaine des capteurs (température, pression, etc.), dans l’imagerie et dans l’éclairage.

Fibre Optique Monomode

Dans une fibre monomode, on obtient un seul mode grâce à la très faible dimension du coeur (diamètre de 10um et moins). Ainsi le chemin de la lumière est imposé, il n’y en a qu’un seul : celui du cœur.

C’est grâce à la fibre monomode qu’il est possible d’atteindre des taux d’atténuation très faibles sur de longues distances. En effet, par une propagation en ligne droite, il n’y a pas d’atténuation due à la réfraction du signal sur la gaine optique (problématique dans le cas d’une fibre multimode). De plus, il n’y a pas de phénomène de dispersion modale (étalement du spectre dû aux différents modes).

Les fibres monomodes sont le plus souvent en association avec des lasers dont la fenêtre centrale est située à 1310 nm et 1550 nm.

Fibre Optique Multimode

Les fibres multimodes (dites MMF, pour Multi Mode Fiber), ont été les premières sur le marché. Elles permettent de transporter plusieurs modes, ie que la lumière peut emprunter de nombreux chemins différents.

Néanmoins, du fait de la dispersion modale, on constate un étalement temporel du signal proportionnel à la longueur de la fibre. En conséquence, elles sont utilisées uniquement sur de courtes distances.

Une fibre multimode est généralement caractérisée par un cœur de fibre variant de 50 à 62,5um. Cependant, ce diamètre peut varier en fonction des constructeurs.

Dans une Fibre Optique multimode, ce sont les fenêtres spectrales de longueurs d’onde 850nm et 1300nm qui sont utilisées.

BiDi GBIC Transceiver Module

BiDi GBIC Transceiver Module

by Fiber-MART.COM

fiber-mart.com offers Single Fiber BiDi GBIC Transceiver Modules designed for optical communications up to 20km with data rates up to 1.25Gbps.

The BiDi GBIC transceiver modules operate on a single strand of standard SMF, and a 1000BASE-BX-D transceiver is always connected to a 1000BASE-BX-U transceiver with a single strand of standard SMF.

 

The communication over a single strand of fiber is achieved by separating the transmission wavelength of the two devices, for example, 1000BASE-BX-D transmits a 1550-nm channel and receives a 1310-nm signal, whereas 1000BASE-BX-U transmits at a 1310-nm wavelength and receives a 1550-nm signal. A wavelength-division multiplexing (WDM) splitter will be integrated into the BiDi SFP to split the 1310-nm and 1550-nm light paths.

 

The 1.25Gbps Single Strand BiDirectional (BiDi) GBIC transceiver modules of fiber-mart.com will undergo strict qualifying tests. In order to ensure the compatibility with those brands such as Cisco, HP, Juniper, Huawei, etc, we will test the BiDi GBIC transceiver module in those related switches and routers. All fiber-mart.com BiDi GBIC transceiver modules are ROHS compliant, allow for real-time diagnostic monitoring as per SFF-8472 and designed to Multi-Source Agreement (MSA) standards.

 

Ordering Information

Part Number	Description
Z-GBIC-GE-BX-U3155-20	1000Base-BX-U BiDi GBIC Module, 1310nm, SMF, 20KM
Z-GBIC-GE-BX-D5531-20	1000Base-BX-D BiDi GBIC Module, 1550nm, SMF, 20KM
Z-GBIC-GE-BX-U3149-20	1000Base-BX-U BiDi GBIC Module, 1310nm, SMF, 20KM
Z-GBIC-GE-BX-D4931-20	1000Base-BX-D BiDi GBIC Module, 1490nm, SMF, 20KM