How Does Fiber Identifier Work In Your Fiber Optic Network

Fiber Optical Identifier is an essential installation and maintenance instrument which can identify the optical fiber by detecting the optical signals transmitted through the cables, during this process the fiber optic identifier do no harm or damage to the fiber cable and it also don’t need opening the fiber at the splice point for identification or interrupting the service.During fiber optic network installation, maintenance, or restoration, it is also often necessary to identify a specific fiber without disrupting live service.

 

The Fiber optic identifier have a slot on the top. The fiber under test is inserted into the slot, then the fiber identifier performs a macro-bend on the fiber. The macro-bend makes some light leak out from the fiber and the optical sensor detects it. The detector can detect both the presence of the light and the direction of light.

 

A fiber optic identifier can detect “no signal”, “tone” or “traffic” and it also indicates the traffic direction. The optical signal loss induced by this technique is so small, usually at 1dB level, that it doesn’t cause any trouble on the live traffic.

 

Fiber optic identifiers can detect 250um bare fibers, 900um tight buffered fibers, 2.0mm fiber cables, 3.0mm fiber cables, bare fiber ribbons and jacketed fiber ribbons. Most fiber identifiers need to change a head fiber optic adapter in order to support all these kinds of fibers and cables. While some other models are cleverly designed and they don’t need to change the head adapter at all. Some models only support single mode fibers and others can support both single mode and multimode fibers.

 

Most high end fiber optic identifiers are equipped with a LCD display which can display the optical power detected. However, this power measurement cannot be used as a accurate absolute power measurement of the optical signal due to inconsistencies in fiber optic cables and the impact of user technique on the measurements.

How to Test Fiber Optic Cables by OTDR

OTDR, full name of which is optical time-domain reflectometer is one of the most popular method of testing the light loss in the cable plant. In most circumstance, it also indicate an fiber optic testing instrument to characterized the optical fibers. OTDRs are always used on OSP cables to verify splicing loss or locating damages to the fiber optic cables. Due to the decline in the OTDR price over recent years, it is more and more applied by technicians for the system installation process.

 

OTDR testing

 

OTDR uses backscattered light of the fiber to imply loss, which is an indirect measurement of the fiber. OTDR works by sending a high power laser light source pulse down the fiber and looking for return signals from backscattered light in the fiber itself or reflected light from connectors or splice interface. OTDR testing requires a launch cable for the instrument to settle down after reflections from the high powered test pulse overloads the instrument. OTDRs can either use one launch cable or a launch cable with a receive cable, the tester result of each is also different.

 

Test With Launch Cable Only

A long lauch cable allows the OTDR to settle down after the initial pulse and provides a reference cable for testing the first connector on the cable. When testing with an OTDR using only the launch cable, the trace will show the launch cable, the connection to the cable under test with a peak from the reflectance from the connection, the under testing cable and likely a reflection from the far end if it is terminated or cleaved. Most terminations will show reflectance that helps identify the ends of the cable.

 

By this method, it can not test the connector on the far end of the under testing cable since it is not connected to another connector, and connection to a reference connector is necessary to make a connection loss measurement.

 

Test With Launch And Receive Cable

By placing a receive cable at the far end of the under testing cable, the OTDR can measure the loss of all factors along the cable plant no matter the connector, the fiber of cables, and other connections or splices in the cable under test. Most OTDRs have a least squares test method that can substract out the cable included in the measurement of every single connector, but keep in mind, this may not workable when the tested cable is with two end.

 

During the process you should always keep in mind to start with the OTDR set for the shortest pulse width for best resolution and a range at least twice the length of the cable you are testing. Make an initial trace and see how you need to change the parameters to get better results.

 

OTDRs can used to detect almost any problems in the cable plant caused during the installation. If the fiber of the cable is broken, or if any excessive stress is placed on the cable, it will show up the end of the fire much shorter than the cable or a high loss splice at the problem locations.

 

Except OTDR testing, the source and optical power meter method is another measurement which will test the loss of the fiber optic cable plant directly, The source and meter duplicate the transmitter and receiver of the fiber optic transmission link, so the measurement correlates well with actual system loss.

DWDM Solutions for Metropolitan Area Network

Today’s services like voice, video and data networks are getting complex and growing tremendous, as well as requiring more bandwidth and faster transmission rates over farther distances. All these cause ferocious competition in the service provider market. And it’s impossible to charge more for the ever-increasing access speed, which resulted in the deployment of DWDM (dense wavelength-division multiplexing) technology in the long-haul transoceanic and terrestrial networks. As DWDM equipment becomes more economical and cost-effective, to deploy them in the metropolitan area network (MAN) is necessary.

 

Why DWDM is Necessary for MANs?

When it comes to DWDM for MANs, many people may ask “Why is DWDM suddenly so popular for MAN applications?” Considering both the DWDM technology and MAN, this question can be discussed from two aspects.

 

The first one is the situation of MAN at present. The practical demands for bandwidth and speed of users affect service providers in the MANs. They have to face problems such as service diversity, bandwidth scalability and fiber exhaustion. Bandwidth scalability deals with the capability of the fiber to carry traffic at exponentially greater speeds. Only by that, the bandwidth provided by service managers may meet the requirements. As for fiber exhaustion, adding more fiber cables may be helpful, but it will cost more and need a long time to finish.

 

Another one is the advantages of deployment DWDM technology. DWDM technology was first deployed on long-haul routes in a time of fiber scarcity. And it finds applications mainly in ultra-high bandwidth long haul as well as in ultra-high-speed metropolitan or inner-city networks, and at the edge of other networks like SONET, SDH and IP. As the ubiquitous deployment of DWDM network and the passive or active DWDM equipment, DWDM technology is expected to be the low-cost solution in MANs and many access-type networks like FTTH and FTTD.

 

Essential DWDM Equipment Used in MAN

As we know, in DWDM networks, multiple wavelengths of light are multiplexed into one single fiber. Therefore, DWDW equipment should be capable of combing or removing signals. Here are three main types of DWDM equipment used in MAN.

 

DWDM Multiplexer and Demultiplexer (DWDM Mux/Demux)

DWDM Mux/Demux modules deliver the benefits of DWDM technology in a fully passive solution. They provide a good solution for long-distance links where wavelengths are packed tightly together over the C-band range of wavelengths, up to 48 wavelengths in 100GHz grid (0.8nm) and 96 wavelengths in 50GHz grid (0.4nm). Usually the common configuration of DWDM Mux/Demux is from 8 channels to 96 channels.

 

DWDM Optical Add/Drop Multiplexer (DWDM OADM)

In order to connect different sites via individual wavelengths, a DWDM system needs to have the capability to add and drop services at distinct locations. That’s why DWDM OADM is needed. OADM can pass-through, remove or add the channels as required. It’s a pass type of DWDM equipment. And the optical losses are different for the add, drop, and pass-through channels.

 

DWDM Erbium-Doped Fiber Amplifier (DWDM EDFA)

Since DWDM network is designed for long runs transmission, the optical power of signals will attenuate with the distances increase. To ensure the quality of signals, DWDM EDFA are used according to the power budget between the transmitter and receiver. Usually based on the used places, there are three common types of fiber amplifiers: booster, in-line amplifier and pre-amplifier. And the gain also can be customized based on specific needs.

 

fiber-mart.COM DWDM Solution for Metropolitan Area Network

Today’s explosion in data traffic, fueled in large part by the growth of the Internet, has caused rapid depletion of available fiber bandwidth in the metropolitan area. The bandwidth bottleneck is now that of the MANs, where capacity has not increased as greatly as the long-haul networks. To meet the demand for long runs transmission in MANs, fiber-mart.COM provides FMT multi-service transport platform for flexible and high density DWDM networking solution. All DWDM equipment like EDFA, OEO, DCM and OLP (optical line protection) come in small plug-in cards, enabling easy installation and management during network deployment. For more details about this DWDM solution, please read this article: Extend DWDM Network Transmission Distance With Multi-Service Transport Platform

How to Store Fiber Optic Cable

Cutting and splicing fiber optic cable takes a lot of time, interrupts service to downstream customers and, therefore, needs to be avoided. One way to avoid splicing is to include extra fiber cable in places along the lines, in case the company needs to change out a pole or make a road crossing. 

 

ETC Communications (ETC) in Ellijay, GA is a family owned company that has been in business for over 100 years. ETC uses fiber optic cable to provide telephone, cable TV, and high-speed Internet to about 17,000 customers in northern Georgia and southeastern Tennessee. They typically include 25 to 50 feet of spare cable approximately every fifth span. The question is…

 

HOW TO STORE THE EXTRA CABLE?

 

Option 1: Coiling

 

Extra cable can be coiled and attached to the pole. However, coiling can cause light loss. In a fiber optic cable, information is transmitted by light that travels through the glass fibers in the cable. Some light is lost when the cable is bent, especially when it is cold. “It does get cold here about four or five times a year,” says  Van Powell, Construction Manager for ETC,  “and when I say cold, I mean below 10°F. When it got below 18°F, we used to have excessive light loss in our long cable runs with lots of coils.” In addition to possible attenuation, coils stored on utility poles take up space and can be damaged by linemen climbing the pole. 

 

Option 2: “Snowshoes”

 

ETC uses “snowshoe” storage systems to store extra fiber on the line. Snowshoes allow for the slack to be stored out in the span, reducing likelihood of damage while eliminating additional charges for using pole space. ETC’s storage systems have a turning diameter of about 20 inches. Two units are installed at an appropriate distance and the cable is stretched between them. This greatly reduces the number of turns--from hundreds to two and solves the problem of light loss.

 

The Opti-Loop® Storage System Advantage

 

ETC has been using products from a couple of different vendors, and last fall, they gave the Hubbell Power Systems, Inc. (HPS) Opti-Loop®  storage systems a try. Powell explains, “There are probably 15 or 20 different companies that make similar systems and we’ve used different kinds in the past. Last year, Phil Peppers, ProCom Sales, brought us five sets of the Opti-Loop storage systems to try them. We put them up, and we like them.” While fiber optic snowshoes, in general, solve the problem, the Opti-Loop storage systems have an advantage: they are very easy to install. “There is a twisted aluminum support wire on the poles. That is what holds up the fiber optic cable. We bring in a bucket truck and attach each snowshoe to that cable with a bolt and clamp. The fiber optic cable is attached to the snowshoes with zip ties and along the support wire with lashers (little coils). It only takes about 15 minutes to mount the pair of snowshoes. The prices for the Opti-Loop storage system is competitive and they are easy and fast to install,” concludes Powell.

The 40G QSFP transceiver Comparison

Data center regularly went through great migration from 1G, 10G to 40G, 100G over the past few decade. Since IEEE 802.3ba standard defined the 40G Ethernet on June 17, 2010. The newest widely adopted optical transceivers is the QSFP+ that offers aggregated optical speeds of 40G. There are many variants for QSFP+ small from factor including LR4 (10km single-mode), IR4 (2km single-mode) or ESR4 and SR4 for short haul multi-mode. So what are they and what is the difference between them? The following passage will provide a satisfying answer to you.

 

QSFP optical transceivers have four separate 10G channels to simultaneously operating for supplying 40GbE network and sum up the capacity into a single channel. The following tables shows QSFP40G portfolio, of which 40GBASE-SR4, 40GBASE-LR4 and 40GBASE-ER4 are the most commonly used 40G physical layers.

 

1. 40GBASE-SR4

40GBASE-SR4 (short range) is a port type for multi-mode fiber and uses 850nm lasers. It uses four lanes of multi-mode fiber delivering serialized data at a rate of 10.3125 Gbit/s per lane. 40GBASE-SR4 has a reach of 100m on OM3 and 150m on OM4. There is a longer range variant 40GBASE-ESR4 with a reach of 300m on OM3 and 400m on OM4. This extended reach is equivalent to the reach of 10GBASE-SR. Take JG325A (see in Figure 2) as an example, it is HP compatible 40GBASE-SR4 QSFP+ transceiver. It primarily enables high-bandwidth 40G optical links terminated with MPO multi-fiber connectors and can also be used in a 4x10G module for interoperability with 10GBASE-SR interfaces.

 

2. 40GBASE-ER4

40GBASE-ER4 (extended range) is a port type for single-mode fiber being defined in P802.3bm and uses 1300nm lasers. It uses four wavelengths delivering serialized data at a rate of 10.3125 Gbit/s per wavelength.

 

3. 40GBASE-LR4

40GBASE-LR4 (long range) is a port type for single-mode fiber and uses 1300nm lasers. It uses four wavelengths delivering serialized data at a rate of 10.3125 Gbit/s per wavelength. Take FTL4C1QE1C as an example, it is Finisar FTL4C1QE1C  (see in Figure 3) compatible 40GBASE-LR4 QSFP+ transceiver supporting link lengths of 10km at a wavelength of 1310nm.

 

Comparison of These Three 40GBASE Standards

Through the above definitions of each type of 40G physical layers, you may have a further understanding of them. Now, we are comparing them one by one. 40GBASE-SR4 is for multi-mode fiber while 40GBASE-LR4 and 40GBASE-ER4 is a port type for single-mode fiber. The multi-mode solutions require special MPO fiber ribbons (multi-strand optical cables) to transport the 4 different 10G optical connections. Single-mode solutions use only two strands of fiber and combine the 4 channels using inexpensive CWDM technology. This gives a tremendous advantage, simplifying the connectivity to standard LC optical connectors and thus reducing costs further.

 

In addition, 40GBASE-LR4 QSFP+ transceivers are most commonly deployed between data-center or IXP sites with single mode fiber. 40GBASE-SR4 QSFP+ transceivers are used in data centers to interconnect two Ethernet switches with 12 lane ribbon OM3/OM4 cables. And from the above figure, we can know that they support different transmission distance in different wavelengths and with different connectors.

 

Summary

To sum up, 40GBASE-SR4, 40GBASE-LR4 and 40GBASE-ER4 are distinguished with each other in several different features—wavelength, connector, transmission distance, etc. fiber-mart.com offers a wide variety of high-density and low-power 40GBASE QSFP+ transceiver modules. They are the best-selling products of our company for its large stocks, competitive price and high quality. In addition, there are also a promotion for MTP cables. For more information, please contact us directly.

SFP28 and QSFP28 Optical Modules For 25 Gigabit Ethernet

The widely acknowledged Ethernet speed upgrade path was 10G-40G-100G. However, a new development indicates the latest path for server connection will be 10G-25G-100G with potential for future upgrading to 400G. But why 25G? Because moving from 10G to 40G is a big jump and it turns out the incremental cost of 25G silicon over 10G is not that great. This new standard will require improved cables and transceiver modules capable of handling this additional bandwidth, under this circumstance, QSFP28 and SFP28 are promoted.

 

25GbE Ethernet—An Emerging Standard

25 Gigabit Ethernet (25GbE) has passed the first hurdle in the IEEE standards body with a successful Call for Interest (CFI) in July, 2014. It is a proposed standard for Ethernet connectivity that will benefit cloud and enterprise data center environments. 25GbE leverages technology defined for 100 Gigabit Ethernet implemented as four 25-Gbit/s lanes (IEEE 802.3bj) running on four fibers or copper pairs. The follow picture shows 25G Access Network.

 

Significant Performance Benefits—25G Over 40G

The value of 25GbE technology is clear in comparison to the existing 40GbE standard. Obviously, 25GbE technology provides greater port density and a lower cost per unit of bandwidth for rack server connectivity. For applications that demand substantially higher throughputs to the endpoint, there exists 50GbE—using only two lanes instead of four—as a superior alternative to 40GbE in both link performance and physical lane efficiency.

 

The proposed 25GbE standard delivers 2.5 times more performance per SerDes lane using twinax copper wire than that available over existing 10G and 40G connections. A 50GbE link using two switch/NIC SerDes lanes running at 25 Gb/s each delivers 25% more bandwidth than a 40GbE link while needing just half the number (four) of twinax copper pairs. Therefore, a 25GbE link using a single switch/NIC SerDes lane provides 2.5 times the bandwidth of a 10GbE link over the same number of twinax copper pairs are used in today’s SFP+ direct-attach copper (DAC) cables.

 

Perhaps the most important benefit of 25GbE technology to data-center operators is maximizing bandwidth and port density within the space constraints of a small 1U front panel. It also leverages single-lane 25Gb/s physical layer technology developed to support 100GbE.

 

Cloud Will Drive to QSFP28 and SFP28

QSFP28 is used for 4x25GE and SFP28 is used for a single 25GE port. SFP28 module, based on the SFP+ form-factor, suports the emeraging 25G Ethernet standard. It enables error-free transmission of 25Gb/s over 100m of OM4 multi-mode fiber and a new generation of high-density 25 Gigabit Ethernet switches and network interface cards, facilitating server connectivity in data centres, and a conventional and cost-effective upgrade path for enterprises deploying 10 Gigabit Ethernet links today in the ubiquitous SFP+ form factor.

 

The QSFP28 (25G Quad Small Form-Factor Pluggable) transceiver and interconnect cable is a high-density, high-speed product soluon designed for applicaons in the telecommunicaons, data center and networking markets. The interconnect offers four channels of high-speed signals with data rates ranging from 25 Gbps up to potentially 40 Gbps, and will meet 100 Gbps Ethernet (4x25 Gbps) and 100 Gbps 4X InfiniBand Enhanced Data Rate (EDR) requirements.

 

The demonstration showed QSFP28-SR4 modules and a compatible Finisar FTLX1471D3BCL 10GBASE-LR SFP+. The QSFP28 SR4 module is a vertically integrated solution that meets IEEE 802.3 standards and MSA requirements with power dissipation well under 3.5W. The module supports both 100GBASE-SR4 as well as 4x25G breakout applications. Both the QSFP28 SR4 and SFP28-SR modules are sampling now.

 

Conclusion

The dominant next-generation server connection speed is going to be 25G as it providing a cost competitive longer reach option for mainstream customers. fiber-mart.com is excited to introduce several products that will drive the next generation of data centre and enterprise interconnects. We currently do not supply 100G QSFP28 and 25G SFP28 based switches, but we do manufacture a full range of tranceivers, such as SFP+, X2, XENPAK, XFP, SFP, GBIC, CWDM/DWDM, 40G QSFP+ & CFP, etc. Compatible Finisar FTLX1471D3BCL and FTLF8524P2BNL are offered with minimum price and high quality. If you are interested, please feel free to contact us.

QSFP+ to 4xSFP+ AOC and QSFP+ MTP Breakout Cable Solution

Migration from 10G to 40G is an inevitable trend in data center. Migration means you need new QSFP+ transceiver modules, fiber patch cables and other equipment. Common two methods to migrate from 10G to 40G for short distance are QSFP+ to 4xSFP+ AOC and QSFP+ MTP breakout cable solution. When you come across this issue, it’s hard to tell which one is better. This article will introduce their difference and tell you how to make the right decision.

 

40G QSFP+ to 4xSFP+ AOC (active optical cable) is composed of a QSFP+ connector on one side and four individual SFP+ connectors on the other side. The QSFP+ connector (40Gbps rate) offers four parallel, bidirectional channels and each operates at up to 10.3125 Gbps. The QSFP+ connector can be installed into QSFP+ port on the switch and feed up to four 10G SFP+ links. And the link lengths can reach 100 meters on OM3 fiber. It’s a cost-effective interconnect solution for 40G and 10G switches and servers.

 

QSFP+ MTP Breakout Cable

The other common solution for 10G to 40G short distance migration is to use breakout cable and of course corresponding transceivers. How to achieve the connection? You’re gonna need 40GBASE-SR4 QSFP+, MTP to LC breakout cable and 10GBASE-SR SFP+. Here we are going to explain 40GBASE-SR4 QSFP+ and MTP-LC breakout cable in details.

 

First, 40GBASE-SR4 QSFP+ is designed for 40 Gigabit data center and can support the link length of 100 m and 150 m respectively on laser optimized OM3 and OM4 fiber cables. This module offers 4 independent channels for transmitting and receiving. Each lane is capable of running 10Gbps signal and is compliant to IEEE 10GBASE-SR specification. Connecting with 12-fiber MTP/MPO cables, it can support 40Gbps network. Or combine 40GBASE-SR4 QSFP+ with 4x10G breakout cable and send data to four 10GBASE-SR SFP+.

 

Second, MTP to LC breakout cable is suitable for high density network. It’s specifically designed for fast Ethernet, fiber channel, data center and gigabit Ethernet application. QSFP+ MTP to LC breakout cable is used for a direct connection between QSFP+ to 4xSFP+ ports with no patch panels or intermediate trunks in between. On one side, it’s an MTP connector with 8 or 12 fibers. On the other side, there are 4 duplex LC connectors. Each fiber cable transmits 10Gbps.

 

Differences of Two Solutions

Two methods of 10G to 40G migration over short distance have been introduced in above content. Comparing the two different solutions, you can find some obvious differences. The following lists some points for your convenience to make suitable decision.

 

Price—The second solution needs at one QSFP+, 4 SFP+ and an MTP-LC breakout cable. The price of these devices is higher than 40G QSFP+ to 4xSFP+ AOC. So 40G QSFP+ to 4xSFP+ AOC is cheaper.

Complexity—The second solution seems more complicated since it needs more optical equipment. You need to order and manage cables.

Distance—40G QSFP+ to 4xSFP+ AOC can only support the distance up to 100 m. While using MTP-LC breakout cable, the link distance can reach 150 m over OM4 cable.

Conclusion

You must have a full understanding of these two solutions. 40G QSFP+ to 4xSFP+ AOC is easier and cheaper than MTP to LC breakout cable. If you’re a new technician and have tight budget, you can buy AOC cable. But if you don’t care too much about money, you can select 40GBASE-SR4 QSFP+ and MTP to LC breakout cable to get a little longer link length. Hope this article can help you make the right decision.

Why Do Scratches Appear After Using the Final Film?

Two of the most frequently asked questions from fiber optic cable assembly operations are:

 

“How do scratches appear?”

“How can we keep scratches to a minimum?”

 

When we receive these questions from a customer, we usually request a visual image of one or more scratches as well as geometry measurements of the connectors. With this information, we try to understand the mechanical parameters applied to the film and connector. This includes various aspects of the entire lapping film operation: the polisher, lapping films, time, pressure, rotation speed, stability, applied fluids, cleaning procedures, and so forth.

 

Why such a thorough investigation? Because scratches might relate to issues in earlier steps in the assembly process. For example, epoxy application, epoxy mixing and/or outgassing, the curing schedule, and encapsulated humidity are common – and surprising – root causes for seeing scratches with a final film. Also, the cleaning operation of the lapping films, connectors, and polishing fixture between polishing steps is often detected as a root cause for scratch generation. In fact, so-called “cross contamination” is common when rough lapping film debris isn’t thoroughly removed when starting with a finer grit abrasive film. (We recommend cost-effective silica carbide abrasive films for excess epoxy removal, followed by a finer grit abrasive film to establish a perfect geometry.)

 

Once we’ve established that the assembly house has a stable lapping film process, we look at the roughness and uniformity of the batch. The visual inspection should show uniform roughness at the typical 0.5-micron or 1-micron level. If the surface roughness isn’t uniform, it likely is caused by one of the example issues mentioned above.

 

Once a uniform batch of connectors or fibers is achieved, as a starting point, we introduce the final film under the same mechanical parameters as the last abrasive film. As the AngstromLap Ultimas Final Polishing Lapping Film deposits its silicon dioxide material on the fiber/ferrule surface, it performs an entirely different chemical reaction than the abrasive films. The silica deposition forms a “coating” over the surface, which offers superior reflection.

 

The four different versions of AngstromLap Ultimas Final Polish Lapping Film (Ultimas-P, Ultimas-U and two Ultimas Flock versions) can address multiple requirements and needs.

 

Here is a very brief overview of the different types of AngstromLap Ultimas Final Polish Lapping Films:

AngstromLap Ultimas-P Final Polish Lapping Film creates a positive fiber height for better physical contact and reflection values.

AngstromLap Ultimas-U Final Polish Lapping Film offers a slight undercut for higher connector matings.

 

AngstromLap Ultimas Flock Final Polish Lapping Film, designed for MTs, eliminates the core-dip on OM3-OM4 fibers and offers superior surface quality.

 

AngstromLap Ultimas Flock Final Polish Lapping Film, designed for large-core fibers (SMA connectors), offers a superior surface quality.

 

Again, when scratches appear after using the final film, this typically relates back to earlier operational steps. It’s important to isolate and correct problematic issues throughout the assembly process. At Fiber Optic Center, we developed the AngstromLap Final Polish Lapping Film and fine-tuned the polishing process for fiber optic connectors.

 

If you have questions about your polishing process, we encourage you to contact us. You can email your question to sales@fiber-mart.com – one of our technical experts will respond as soon as possible. Our goal is to help you make the best fiber optic cable assemblies in the world.

Fiber Splitter for FTTH Applications

Passive optical network (PON) has been widely applied in the construction of FTTH (fiber to the home). With PON architecture, network service providers can send the signal to multiple users through a single optical fiber, which can help them save great costs. To build the PON architecture, optical fiber splitter is necessary.

 

What Is Fiber Splitter?

The fiber splitter is a passive component specially designed for PON networks. Fiber splitter is generally a two-way passive equipment with one or two input ports and several output ports (from 2 to 64). Fiber splitter is used to split the optical signal into several outputs by a certain ratio. If the ratio of a splitter is 1×8 , then the signal will be divided into 8 fiber optic lights by equal ratio and each beam is 1/8 of the original source. The splitter can be designed for a specific wavelength, or works with wavelengths (from 1260 nm to 1620 nm) commonly used in optical transmission. Since fiber splitter is a passive device, it can provide high reliability for FTTH network. Based on the production principle, fiber splitters include Planar Lightwave Circuit (PLC) and Fused Bionic Taper (FBT).

 

PLC Splitters

PLC splitters are produced by planar technology. PLC splitters use silica optical waveguide technology to distribute optical signals from central office to multiple premise locations. The output ports of PLC splitters can be at most 64. This type of splitters is mainly used for network with more users.

 

The Structure of PLC splitters

Internal Structure

 

The following figure shows a PLC splitter. The optical fiber is splitted into 32 outputs. PLC chip is made of silica glass embedded with optical waveguide. The waveguide has three branches of optical channels. When the light guided through the channels, it is equally divided into multiple lights (up to 64) and transmitted via output ports.

 

Outside Configuration

 

Bare splitter is the basic component of PLC fiber splitter. For better protection of the fragile fiber and optimized use, PLC splitters are often equipped with loose tube, connector and covering box. PLC splitters are made in several different configurations, including ABS, LGX box, Mini Plug-in type, Tray type, 1U Rack mount, etc. For example, 1RU rack mount PLC splitter (as shown in the figure below) is designed for high density fiber optical distribution networks. It can provide super optical performance and fast installation. This splitter is preassembled and fibers are terminated with SC connectors. It’s ready for immediate installation.

 

rack-mount-plc-spllitter

 

FBT Splitters

FBT splitters are made by connecting the optical fibers at high temperature and pressure. When the fiber coats are melted and connected, fiber cores get close to each other. Then two or more optical fibers are bound together and put on a fused taper fiber device. Fibers are drawn out according to the output ratio from one single fiber as the input. FBT splitters are mostly used for passive networks where the split configuration is smaller.

 

PLC Splitters From fiber-mart.COM

Fiberstore offers a wide range of PLC splitters that can be configured with 1xN and 2xN. Our splitters are designed for different applications, configurations including LGX, ABS box with pigtail, bare, blockless, rack mount package and so on.

 

Conclusion

Fiber splitter is an economical solution for PON architecture deployment in FTTH network. It can offer high performance and reliability against the harsh environment conditions. Besides, the small sized splitter is easy for installation and flexible for future network reconfiguration. Therefore, it’s a wise choice to use fiber splitter for building FTTH network.

 

Why are MTP/MPO patch cords widely used?

With the continuous development of big data and cloud computing, the demand for high bandwidth and high-speed network has increased greatly. However, solving this problem often costs a great deal, the emergence of MTP/MPO patch cords is a good solution to this problem. Following we will analyze the MTP/MPO patch cord for everyone.

 

What is MTP/MPO patch cord?

The MTP/MPO patch cord consists of a connector and a section of optical cable. According to the number of fiber core, it can be divided into 8 cores, 12 cores, 24 cores, 48 cores and 72 cores. And it has two types of connectors, male head connector and female head connector.The biggest difference between the two connectors is that the former has stitches, and the latter does not. In addition, the push and pull design of MTP/MPO optical fiber jumper can make insertion and disassembly more convenient and fast, thus saving wiring time.

 

Why use the MTP/MPO patch cord?

With the increasing demand for data centers, the traditional optical fiber not only reduces the space utilization of data centers, but also increases the difficulty of the management of the wiring system. The MTP/MPO fiber jumper greatly improved the space utilization of the data center, so now MTP/MPO patch cord is widely used.

 

Application of MTP/MPO patch cord

High density optical fiber link

Communications and CATV networks

Data center cabling system

LAN and WAN user side

 

Structure of MTP/MPO patch cord

Because the structure of MTP/MPO patch cord connector is complex, it should be used carefully. So it's important to understand the structure of the MTP/MPO patch cord connector.

As shown below, the MTP/MPO connector has a key bond on the side. In this direction, each fiber hole in the connector is numbered from left to right, P1, P2, P3 etc. In addition, when the connector is inserted, a white spot on the connector points to the P1 side.

 

Advantages of MTP/MPO patch cord

Small diameter and smaller volume, so the wiring space is increased.

The connector's special design can eliminate termination errors and substantially saves installation time.

According to the user's different configuration requirements, can select the corresponding MTP/MPO patch cord structure to meet the different wiring requirements.

Its components have excellent optical and mechanical properties, so insertion loss is low in high speed network environments.

The use of micro cable to maximize the bending radius, and the size and volume are relatively small.

 

MTP/MPO patch cord is widely used in high-density cabling system, with small space occupancy, and can save installation time and cost. It is an ideal solution for high-density routing environment. As an important technology for upgrading to 40/100G Ethernet, MTP/MPO optical patch cord is being used by more and more people.

Cisco Gigabit Ethernet SFP Transceiver Modules introductions

SFP (Small Form-Factor Pluggable) transceiver is a hot swappable I/O device that plugs into a Gigabit Ethernet port or slot, linking the port with the network. Gigabit Ethernet SFP transceivers are designed to use with Gigabit networks. They are compliant to IEEE 802.3 standards and with different types to fit for 1000Base SX, LX/LH, EX and 1000Base-T applications.

 

It is important to choose a proper Gigabit Ethernet transceiver to act as an interface between the device and the cable. The interconnecting cable can be made of copper or fiber optic. This choice of transceiver is usually made based on the type of fiber optic cable.

 

Cisco Gigabit Ethernet SFP Transceiver Modules mainly include 1000BASE-T (or GLC-T) SFP, 1000BASE-SX SFP, 1000BASE-LX/LH SFP, 1000BASE-EX SFP, 1000BASE-ZX SFP, 1000BASE-BX10-D and 1000BASE-BX10-U SFP.

 

1000BASE-T (or GLC-T) SFP: Cisco GLC-T is a copper wire SFP for 1000Base-T applications. The 1000BASE-T SFP operates on standard Category 5 unshielded twisted pair copper cabling of up to 100m length. Cisco 1000BASE-T SFP module supports 10/100/1000 auto-negotiation and Auto MDI/MDIX.

 

1000BASE-SX SFP: 1000Base-SX SFP supports Multimode fiber only. It operates on 50μm multimode fiber links up to 550m, up to 1km over laser-optimized 50μm multimode fiber cable and on 62.5μm Fiber Distributed Data Interface (FDDI)-grade multimode fibers up to 220m.

 

1000BASE-LX/LH SFP: 1000BASE-LX supports both Multimode and Single-mode fibers. 1000BASE-LX/LH SFP operates on standard single-mode fiber optic link spans of up to 10km and up to 550m on any multimode fibers.

 

1000BASE-EX SFP: The 1000BASE-EX SFP supports for Single-Mode Fibers. 1000BASE-EX SFP operates on standard single-mode fiber-optic link length up to 40 km. A 5-dB inline optical attenuator should be inserted between the fiber-optic cable and the receiving port on the SFP at each end of the link for back-to-back connectivity.

 

1000BASE-ZX SFP: The 1000BASE-ZX SFP operates on standard single-mode fiber-optic link spans of up to approximately 70 km in length. The SFP provides an optical link budget of 23 dB, but the precise link span length depends on multiple factors such as fiber quality, number of splices, and connectors.

 

1000BASE-BX10-D and 1000BASE-BX10-U SFP: The 1000BASE-BX-D & 1000BASE-BX-U SFPs used for Single-Fiber Bidirectional applications. A 1000BASE-BX10-D device is always connected to a 1000BASE-BX10-U device with a single strand of standard SMF with an operating transmission range up to 10km.

 

The communication over a single strand of fiber is achieved by separating the transmission wavelength of the two devices. 1000BASE-BX10-D transmits a 1490-nm channel and receives a 1310-nm signal, whereas 1000BASE-BX10-U transmits at a 1310nm wavelength and receives a 1490nm signal. Wavelength-division multiplexing (WDM) splitter integrated into the SFP to split the 1310nm and 1490nm light paths, up to 80km or 1000base BX-D BIDI tx1550 rx1490nm 80km in simple.

How to Convert a QSFP+ Port to a SFP+ Port?

As data communications technology migrates from 10GbE to 40GbE and beyond, it is often necessary to connect 40GbE equipment with existing 10GbE equipment. As we know 40GbE NIC or switch usually equipped with QSFP+ ports, and 10GbE switch usually equipped with SFP+ ports. That is to say we must know how to convert a QSFP+ port to a SFP+ port. At present, there exists three ways to solve this problem.

 

QSFP+ to SFP+ Cable

As shown in the figure below, a QSFP+ to SFP+ cable consists of a QSFP+ transceiver on one end and four SFP+ transceivers on the other end. The QSFP+ transceiver connects directly into the QSFP+ access port on the switch. The cables use high-performance integrated duplex serial data links for bidirectional communication on four links simultaneously. The SFP+ links are designed for data rates up to 10 Gbps each. QSFP+ cable is available in passive and active two types. Passive QSFP+ cable has no signal amplification built into the cable assembly, therefore, their transmission distance is usually shorter than an active one.

 

QSFP+ to SFP+ Adapter (QSA)

You can convert a QSFP+ port to a SFP+ port using the QSFP+ to SFP+ adapter. QSA provides smooth connectivity between devices that use 40G QSFP+ ports and 10G SFP+ ports. Using this adapter, you can effectively use a QSFP+ module to connect to a lower-end switch or server that uses a SFP+ based module. This adapter is very easy to use. As shown in the figure below, just plug one side of the QSA in your QSFP+ port, and plug a SFP+ module into another side of the QSA. Then you can convert a QSFP+ port to a SFP+ port easily.

 

 

QSFP+ Breakout Cable

As we know, parallel 40GBASE-SR4 QSFP+ modules use 8 out of 12 MPO/MTP interface fibers transmitting 4 x duplex (DX) channels (4 x transmit and 4 x receive). The QSFP+ breakout cable uses a pinless MTP connector on one end for interfacing with the QSFP port on the switch. The other end contains 4 duplex LC connectors, which provide connectivity to the SFP+ ports on the switch. Thus higher-speed equipment (40G QSFP+) can be connected to slower-speed equipment (10G SFP+) successfully.

 

Conclusion

When you want to connect a QSFP+ port to a SFP+ port, you can use QSFP+ to SFP+ cable, QSFP+ to SFP+ adapter or QSFP+ breakout cable. All these three options can meet your needs. fiber-mart.com provides a full range of compatible QSFP+ cable, which can be 100% compatible with your Cisco, Juniper, Arista and Brocade switches and routers. Or you want to use QSFP+ breakout cable, you can also find it in our fiber-mart.com.

what types of Fiber Optic Adapter?

A small equipment used for connecting optical fiber cables together is often called as fiber optic adapter or fiber optic coupler. Although they may shape differently, they have the same function. A fiber optic adapter allows fiber optic cables to be attached to each other singly or in a large network, permitting many devices to communicate at once. According to different shapes and structures, fiber optic adapters can be classified in several types, such as FC fiber optic adapter, SC fiber optic adapter, ST fiber optic adapter, LC fiber optic adapter and so on. And this article will particularly introduce these four kinds of fiber optic adapters.

 

FC Fiber Optic Adapter

FC fiber optic adapter uses a metal sleeve to strengthen its outer structure and can be fastened by a turnbuckle. It also adopts the ceramic pins as its butt end. Therefore, FC fiber optic adapter is able to sustain a stable optical and mechanical performance for a long time. It can be divided into square type, oval type and round type in single-mode and multimode versions. FC fiber optic adapter is easy to operate but sensitive to dust, so it has been enhanced today by using spherical butt end without changing its external structure.

 

SC Fiber Optic Adapter

Covered with a rectangular shell, SC fiber optic adapter has the same configuration and size of the coupling pin cover as FC fiber optic adapter. From its structures, SC fiber optic adapter can be classified into simplex standard, duplex standard and shuttered standard. From its materials, metal and plastic are commonly used for SC fiber optic adapter. SC fiber optic adapter enables a high precision alignment with a low insertion, return loss and back reflection.

 

ST Fiber Optic Adapter

ST fiber optic adapter has a key snap-lock structure to ensure accuracy when connecting the cables together. The repeatability and durability of ST fiber optic adapter is improved by the metal key. With a precised ceramic or copper cover, ST fiber optic adapter can also keep a high optical and mechanical performance for a long time. It has two standards of simplex and duplex and uses the metal or plastic housing.

 

LC Fiber Optic Adapter

LC fiber optic adapter adopts the modular jack latch mechanism which is easy to operate. Using the smaller pins and sleeves, LC fiber optic adapter greatly increases the density of fiber optic connector. There are three types of LC fiber optic adapter in simplex, duplex and quad structures.

 

Applicable End Faces

Different fiber optic adapters supports different ends faces. PC (physical contact), UPC (ultra physical contact) and APC (angle physical contact) are the polish style used for fiber optic adapters. ST fiber optic adapter is only available with PC and UPC styles. But except ST, the rest three fiber optic adapters support all the polish styles. Moreover, the color of fiber optic adapters can be used to define different end faces of PC, UPC and APC. For example, as for SC and LC fiber optic adapters, there are cream, blue and green colors which correspond to PC, UPC and APC end faces.

 

Application

In order to help the signal transmission, fiber optic adapter is widely used for telecommunications system, cable TV network, LAN (local area network), WAN (wide area network), FTTH (fiber to the home), video transmission and instrument testing. It is no doubt that fiber optic adapter is of great help for network communications.

 

Conclusion

Fiber optic adapter provides convenience for fiber cable connections. FC, SC, ST, LC fiber optic adapters are parts of the adapter family and are widely adopted in practical use. Small device like fiber optic adapter really helps a lot for different applications in life, because it greatly improves the working efficiency.

How the Fiber Optics Attenuators work?

An optical attenuator is a passive device used to reduce the power level of an optical signal, either in free space or in an optical fiber. There are various types of them from the fixed ones, step-wise variable, and continuously variable.

 

Attenuators are usually used when the signal arriving at the receiver is too strong and hence may overpower the receiving elements. This may occur because of a mismatch between the transmitters/receivers, or because the media converters are designed for a much longer distance than for which they are being used.

 

Sometimes attenuators are also used for stress testing a network link by incrementally reducing the signal strength until the optical link fails, determining the signal’s existing safety margin.

 

Although fiber optic attenuators are normally used in SM (Single Mode) circuits, because this is where the stronger lasers are used for distance transmission, there are also multi mode attenuators available.

 

The most common version of attenuators are male to female units, often called plug-style or buildout style. These plug-style attenuators simply mount on one end of a fiber optic cable, allowing that cable to be plugged into the receiving equipment or panel.

 

There are also female to female (bulkhead) attenuators, often used to mount in patch panels or for connecting two fiber optic cables together. More expensive, but useful for testing, are variable attenuators which are adjustable between 1dB and 30dB.

 

Fiber optic attenuators are usually used in two scenarios.

 

The first case is in power level testing. Optical attenuators 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, optical attenuators are permanently installed in a fiber optic communication link to properly match transmitter and receiver optical signal levels.

 

How many types of Optical Attenuators (OA) can you find?

 

There are four different types of OA and they can take a number of different forms and are typically classified as fixed or variable attenuators. What's more, they can be classified as LC, SC, ST, FC, MU, E2000 etc. according to the different types of connectors.

 

1. Fixed Attenuators: Fixed optical attenuators used in fiber optic systems may use a variety of principles for their functioning. Preferred attenuators use either doped fibers, or misaligned splices, or total power since both of these are reliable and inexpensive.

 

 

 

Inline style attenuators are incorporated into patch cables. The alternative build out style attenuator is a small male-female adapter that can be added onto other cables. 

 

Non-preferred attenuators often use gap loss or reflective principles. Such devices can be sensitive to modal distribution, wavelength, contamination, vibration, temperature, damage due to power bursts, may cause back reflections, may cause signal dispersion etc.

 

2. Loopback Attenuators: Loopback fiber optic attenuator is designed for testing, engineering and the burn-in stage of boards or other equipment. Available in SC/UPC, SC/APC, LC/UPC, LC/APC, MTRJ, MPO for single mode application. 

 

 

3. Built-in Variable Attenuators: Built-in variable optical attenuators may be either manually or electrically controlled. A manual device is useful for one-time set up of a system, and is a near-equivalent to a fixed attenuator, and may be referred to as an "adjustable attenuator". In contrast, an electrically controlled attenuator can provide adaptive power optimization.

 

Attributes of merit for electrically controlled devices, include speed of response and avoiding degradation of the transmitted signal. Dynamic range is usually quite restricted, and power feedback may mean that long-term stability is a relatively minor issue.

 

The speed of response is a particularly major issue in dynamically reconfigurable systems, where a delay of one millionth of a second can result in the loss of large amounts of transmitted data.

 

Typical technologies employed for high-speed response include liquid crystal variable attenuator (LCVA), or lithium niobate devices.

 

There is a class of built-in attenuators that is technically indistinguishable from test attenuators, except they are packaged for rack mounting, and have no test display.

 

4. Variable Optical Test Attenuators: this type generally uses a variable neutral density filter. Despite the relatively high cost, this arrangement has the advantages of being stable, wavelength insensitive, mode insensitive, and offering a large dynamic range.

Everything You Need to Know About SFP Transceivers

by www.fiber-mart.com

SFP is the short form of Small Form-factor Pluggable. It is a transceiver which we use widely in the field of networking and data communication. It is a hot pluggable and compact device and behaves as an interface between a networking device and its interconnecting cable. The cable could be a copper cable or it can be an optical fiber cable, it performs conversions between electrical and optical signals.

SFP supports many standards such as Ethernet, SONNET, Fiber Channel etc. it can allow transport of gigabit and other fast Ethernet LAN packets over time division multiplexing based WANs, also it can help in transmission of E1/T1 streams over packet switched networks. SFP is an upgraded version of GBIC module i.e. Gigabit interface converter that’s why it is also called mini GBIC, it has very similar functionality as GBIC transceiver but has much smaller dimensions. The SFP permits greater port density (number of transceivers per inch along the edge of a mother board) than the GBIC.

The form factor and electrical interface are specified by the multi-source agreement (MSA) under the auspices of the Small Form Factor Committee. It is a famous industry developed and supported by many network component vendors.

In markets, SFP have a wide range of devices which are easily detachable and can allow users to select the appropriate transceiver according to the required optical range for the network. Copper cable interfaces allow a host device designed primarily for fiber optic communications, for the purpose to communicate over unshielded twisted pair networking cables.

SFP transceiver support various digital diagnostics monitoring functions and are called digital optical monitoring (DOM), with this feature, users can monitor real time parameters of SFP, some of which are output power, temperature, input power, transceiver supply voltage, laser bias current etc.

An enormous amount of change is expected in optical transceiver, each with different transmitter or receiver, this allows the client to customize and configure the transceiver to get the proper reach with either a multi mode fiber or single mode fiber type. The single form factor pluggable comes in different categories namely –SX, which is 850nm, LX, which is 1310nm, ZX, which is 1550nm and DWDM. These categories have an interface of a copper cable which allows a mother board to communicate via USTP (unshielded twisted pair) cable network.

The SFP has the transfer rate of approx. 4.25 Gbit/s while XFP, which is another form factor and very identical to SFP, increases this amount by three times i.e. 10Gbit/s.

In this article we will discuss various SFPs and how they are different from each other by comparing them and formulate a table.