Category: Fiber Transceivers

Fusion splicer is a device using an electric arc to melt two optical fibers together at their end faces and form a single long fiber. The resulting joint, or fusion splice, permanently joins the two glass fibers end to end, so that optical light signals can pass from one fiber into the other with very little loss. There are numerous well-known brands of fusion splicer such as Fujikura, CLETOP, EXFO, Noyes, AFL ect. The most famous brand of these is Fujikura. This text mainly introduces Fujikura fusion splicer.

Fujikura Ltd. is a global, Tokyo-based electrical equipment manufacturing company. It develops and manufactures power and telecommunication systems products, including devices for optical fibres, like cutters and splicers. As the leading splicer brand in the world, Fujikura achieves and maintains the leading splicer brand in the world by providing quality products, extensive knowledge to telecommunication, photonics research and manufacturing application.

Fujikura fusion splicer is one of the most widely used device in the world, and known for its performance, productivity and reliability. Fujikura fusion splicer keeps good condition as master’s tool to maintain good quality. And all Fujikura’s fusion splicers are backed by Fujikura’s Technical Support team. Fujikura has over 80 of authorized distributors all over the world. They stand by you and give the best and the quickest support, not only after service, but also before. You can depend on them for a solution to your every problem.

According to different splicing applications, Fujikura fusion splicer can be classified into three types: core alignment splicer, ribbon fiber fusion splicer and special fiber fusion splicer. Core alignment splicer is mostly used in practice, which includes 70S, 19S. Ribbon fiber fusion splicer is an essential tool to work effcient, which includes 70R, 19R and 12R. Special fiber fusion splicer includes fiber-martM-100 series, specialty accessories and recoater.

Fujikura has developed a comprehensive range of fusion splicer products to satisfy for every application. Although Fujikura constantly keep improving and innovating, it has invented the fiber-martM-80S Alignment Fusion Splicer succeeding to Fujikura FMS 60s fusion splicer. The main features of Fujikura fiber-martM-80S  in comparison with the fiber-martM-60S as following:

New Li-Ion battery now allows you to make up to 200 splicing cycles-shrinking

High speed welding of fiber (7c for single-mode fiber)

High speed shrink (14c CRSS 60mm)

Increased lifetime of electrodes – up to 3000 splices

Splicing with a length of just 5mm cleavage for use with any welded connectors or for micro-CRSS (20mm, 30mm)

Review System without mirrors

Automatic closing windproof lid when downloading and opening the fiber at the end of the welding

It is obvious that fiber-martM-80S has plenty of advantages over older ones in many aspects. Today, fiber-martM-80S splicer is the new standard model to cover  varied splicing needs in those fields. Also, it is just one of the  typical device of Fujikura fusion splicer.

FTTH (fiber to the home) networks are installed in many areas covering indoor section, outdoor section, as well as the transition in between. To fulfill the cabling requirements from different areas, different types of fiber optic cable are well developed. Drop cable as an important part of FTTH network forms the final external link between the subscriber and the feeder cable. This blog post will focus on this special outdoor fiber optic cable.

The Basic of FTTH Drop Cable

Drop cables, as previously mentioned, are located on the subscriber end to connect the terminal of a distribution cable to a subscriber’s premises. They are typicality small diameter, low fiber count cables with limited unsupported span lengths, which can be installed aerially, underground or buried. As it is used in outdoor, drop cable shall have a minimum pull strength of 1335 Newtons according to the industry standard. Drop cables are available in many different types. The following part introduces three most commonly used drop cables divided according to the cable structure.

Flat Type Drop Cable, also known as flat drop cable, with a flat out-looking, usually consists of a polyethylene jacket, several fibers and two dielectric strength members to give high crush resistance. Drop cable usually contains one or two fibers, however, drop cable with fiber counts up to 12 or more is also available now. The following picture shows the cross section of a flat drop cable with 2 fibers.

Figure-8 Aerial Drop Cable is self-supporting cable, with the cable fixed to a steel wire, designed for easy and economical aerial installation for outdoor applications. This type of drop cable is fixed to a steel wire as showed in the following picture. Typical fiber counts of figure-8 Drop Cable are 2 to 48. Tensile load is typically 6000 Newtons.

Round Drop Cable usually contains a single bend-insensitive fiber buffered and surrounded by dielectric strength members and an outer jacket, which can provide durability and reliability in the drop segment of the network. The following shows the cross section of a round drop cable with one tight buffered optical fiber.

Drop Cable Connectivity Method: Splice or Connector?

It’s necessary to choose a right architecture for FTTH network from overall. However, drop cable as the final connection from the fiber optic network to customer premises also plays an important role. Thus, finding a flexible, efficient and economical drop cable connectivity method becomes a crucial part of broadband service. Whether to use a fiber optic connector, which can be easily mated and un-mated by hand or a splice, which is a permanent joint? The following will offer the answer and the solutions for your applications.

It is known that splice, which eliminates the possibility of the connection point becoming damaged or dirty with a permanent joint, has better optical performance than fiber optic connector. However, splice lack of operational flexibility compared with fiber optic connector. Fiber optic connector can provide an access point for networking testing which cannot be provided by splicing. Both methods have their own pros and cons.

Generally, splice is recommended for drop cables in the places where no future fiber rearrangement is necessary, like a greenfield, new construction application where the service provider can easily install all of the drop cables. Fiber optic connector is appropriate for applications which flexibility is required, like ONTs which have a connector interface.

Choosing the Right Splice Method

For splice, there are two methods, one is fusion splicing, the other is mechanical splicing. Fusion splicers have been proved to provide a high quality splice with low insertion loss and reflection. However, the initial capital expenditures, maintenance costs and slow installation speed of fusion splicing hinder its status as the preferred solution in many cases. Mechanical splicing are widely used in FTTH drop cable installation in countries, as a mechanical splice can be finished in the field by hand using simple hand tools and cheap mechanical splicer (showed in the following picture) within 2 minutes. It’s a commonly used method in many places, like China, Japan and Korea. However, in US mechanical splicing is not popular.

Choosing the Right Connector

For fiber optic connector, there are two types connector for drop cable connection. Field terminated connector, which contains fuse-on connector and mechanical connector, and pre-terminated drop cable, which is factory terminated with connector on the end of drop cable.

Fuse-on connector uses the same technology as fusion splicing to provide the high optical connection performance. However, it requires expensive equipment and highly trained technician, and more time like fusion splicing. Mechanical connector could be a replacement of fuse-on connector (showed in the following picture), if the conditions do not fit the mentioned ones. It could be a time-save and cost-save solution for drop cable termination.

If you have no limits in cost and want high performance termination in a time-save way, pre-terminated drop cable could be your choice. Many factories can provide you customized drop cables in various fiber types, fiber optic connector and lengths.

Conclusion

Customer demand for higher bandwidth will continue to drive the development of FTTH as well as its key component like drop cable. Choosing the right drop cable and drop cable termination method is as important as choosing the right network architecture in FTTH.

Loopback

Loopback is a commonly used term in telecommunications. It refers to the process of transmitting electronic signals or digital data streams and returning to their sending point without any intentional processing or modification. Therefore, by comparing transmitting signals with the receiving signals, the loopback test is used to debug physical connection problems. But what a loopback test means for fiber optic network and how to make use of it will be the issues that we will explore in this post.

Why Need Fiber Loopback Test?

To conduct a fiber loopback test, the communication devices will be involved, like the transceivers and the switch. As you know, the transceiver is the basic component of fiber optic communication network equipment. We can take the transceiver as a case. Conventionally, a transceiver has a transmitting port and a receiving port, in that way, the loopback test can be applied to test the ports to diagnose whether the transceiver is working well and the configuration of the switch is right. For its unique working mode, the test is a convenient way to maintain transceivers. In the next part, we will deliver how to do the fiber loopback test on the transceiver.

How to Conduct Loopback Test?

In this part, we will introduce two types of tests to troubleshoot transceiver and switch port: single-port test and dual-port test.

Tools You Need to Prepare

To perform tests, things you need to prepare are listed below:

Transceivers (2pcs), such as 10G SFP+ SR transceiver.

Simplex fiber cable (1 pc).

Switch (1 pc), like Cisco switch.

Duplex fiber cable (1 pc).

Two loopback cables (optional), like LC or SC loopback cable. To know more about loopback cable, you can move to the article: What Is Loopback Cable And How to Use It?

1. Connect your transceiver with one simplex fiber cable or loopback cable, such as LC fiber cable or LC loopback cable. At this step, you can examine whether the port and transceiver parameters are normal.

2. Check the software version of the switch.

3. Review the interfaces status to confirm the working status of all ports on the switch.

4. Check the working status of the port you are connecting, such as the port 50 in the following figure.

5. Go over the DDM information to review whether the transceiver works in normal status.

1. Connect two transceivers with one duplex fiber cable or two loopback cables. At this step, you can examine whether the port and transceiver data rate are matching as well as the link is normal or not.

2. Check the interfaces status to confirm the working status of all ports on the switch.

3. Check the working status of the two ports you are connecting, such as the ports 50 and 52 in the following figure.

4. Go over the DDM information to review whether the transceiver works in normal status.

Summary

To troubleshoot the circuit connectivity as well as the transceiver and the switch port, loopback test is a cost-effective way. In this post, we have an overview of loopback and make a demonstration of how to conduct the loopback test on a switch to debug the transceiver and the switch port.

As a passive technology, CWDM allows for any protocol to be transported over fiber optic link at specific wavelengths. CWDM technology is a cost-effective and simple method to increase the capacities of fiber optic network, by using different wavelengths to carry different signals over a single optical fiber. The wide deployment of CWDM network is greatly driven by its affordable cost.

What Is Need for A 10G CWDM Network?

The deployment of a 10G CWDM network is relaying on the exiting fiber optic network. Adding some components on the existing network can largely increase its capacity for data transmission. Here will introduce the key component and an important step during 10G CWDM network deployment.

A Key Component—CWDM Mux/Demux

A key component should be deployed is CWDM Mux/Demux, which combines different wavelength signals from different optical fibers into a single optical fiber, or separates different wavelength signals coming from a single optical fiber to separate optical fibers. The Channel number of a CWDM Mux/Demux is an important factor to divide this device. Standards have identified 18 CWDM Channels. Most of the CWDM Mux/Demux are provided with Channel number range from 2 to 16. However, fiber-mart.COM provides a 18-Channel CWDM Mux/Demux which can increase capacity of CWDM network to the most. CWDM Mux/Demuxs also come into a variety of package form factors. The most commonly used are LGX design, rack design and pigtail design.

An Important Step—Connecting CWDM Mux/Demux With 10G Switch

Connecting CWDM Mux/Demux with a 10G switch, is the most important step to build a 10G CWDM network. In simple, to add more devices on the fiber optic network by CWDM technology is to connect the CWDM Mux/Demux with the 10G switches which are linked to the end users. To link CWDM Mux/Demux with the switches, fiber patch cable and 10G CWDM SFP+ transceiver are needed. 10G CWDM SFP+ transceiver should be installed on the switch SFP+ port (some switches use XFP port, then 10G CWDM XFP transceiver is required). Then a length of fiber patch cable should be used to link the transceiver and CWDM Mux/Demux.

How to Select to Right 10G CWDM SFP+ Transceivers?

Choose the Right Working Wavelength: To ensure the right connection, the specific wavelength port should be connected to the same wavelength CWDM SFP+ transceivers. For example, the port on the CWDM Mux/Demux marked with 1270 nm, should be connected to a CWDM SFP+ transceiver that working over wavelength of 1270 nm. As there are 18 different CWDM wavelengths, 10G CWDM SFP+ transceivers that are provided in the market also can 18 different versions for these wavelengths.

Choose the Compatible CWDM SFP+: It is common sense that the fiber optic transceiver should be compatible with the switch which it works on. For instance, if you are using a Cisco switch, the fiber optic transceivers that you used with this switch should be original Cisco transceivers or Cisco compatible transceivers which are provided by third party vendors. The latter is usually the choice of many companies, this is because third party transceivers are usually more cheap than the original brand transceivers. Fiber optic transceivers provided by third party vendor like fiber-mart.COM are all fully tested on original brand switch to ensure their compatibility and quality. What’s more, most of fiber-mart.COM fiber optic transceivers support same day shipping. Select the right SFP do not only cut your cost and time, but also provide high network performance.

Choose the Transmission Distance According to Your Needs: CWDM network is usually deployed for long distance transmission. Thus the 10G CWDM SFP+ transceiver that are provided in the market usually support transmission distance longer than 20 km, some can support link length up to 80 km or more. You can select the 10G CWDM SFP+ according to your requirements.

SFP cable, also known as 10G SFP+ cable, SFP+ DAC twinax cable or SFP+ AOC cable, is a form of high speed cable with Small Form Factor Pluggable Plus on either end. They are suitable for in-rack connections between servers and switches. SFP cable’s popularity can be attributed to that Cat5e copper cabling and 1000BASE-T have dominated data center interconnection application for years, however, the upgrading to 10GE, 40GE and beyond poses a significant hindrance in both power consumption and cost. At this point, 10G SFP+ direct attach copper swoops in and becomes a new favor of Top of rack switching.

What Is SFP Cable?

SFP twinax cable which replaces two optical modules and a connectorized optical fiber with a twinaxial copper cable assembly offers the higher density, lower cost, and lower power 10 Gigabit Ethernet solution than other cable types such as 10GBASE-CX4 and CAT6/CAT6A 10GBASE-T. The SFP cables can be classified to 10G SFP+ DAC cable and 10G SFP+ AOC cable. SFP+ AOC features longer transmission distances(>100m), isolation from signal interference and crosstalk and higher signal transmission capacities but it’s more expensive than SFP+ DAC. SFP+ DAC consists of active DAC and passive DAC. Passive DAC cables have no signal amplification built into the cable assembly hence for ultra short reach(<5m), whereas active DAC cables have signal amplification and equalization built into the cable assembly for a litter longer reach(5-15m) in the same time with a higher price.

SFP Cable: 10G SFP+ Cable vs. 25G SFP28 Cable

We’ve already known that SFP+ is made to operate at 10Gb/s. And SFP28, as the enhanced version of SFP+, is designed for 25G signal transmission. SFP28 utilizes the same familiar form factor as SFP+, but the electrical interface is upgraded to handle 25Gbps per lane. To put it simply, 10G SFP+ cable and 25G SFP28 cable just has the same form factor but with different speed. What’s more, 25G SFP ports can support a full range of 10G SFP+, which means 10G SFP+ cable can be plugged into 25G SFP ports.

How SFP Cable Is Used?

As 10G network is widely deployed in today’s data center, 10G SFP cables are commonly used in interconnect applications below 100m, such as server to switch or storage to switch interconnection in the same rack (Shown in the below picture). And now 25GbE is popular and 25G direct attach cable assemblies, such as SFP28 DACs, are already available in the market. For 40GbE, 40G QSFP+ DACs and AOCs are used. Of course, higher speed and more bandwidth are needed for spine switches. Thus, 100G DACs, like QSFP28 DACs are used in this case.

Conclusion

With the convenience of plug and play technology, fiber-mart.COM’s family of 10G SFP cable delivers throughput that exceeds those of industry standards. Besides, they also offer a variety of high speed interconnect DAC assemblies including 40G/56G QSFP+ cable, and 100G QSFP28 cables to satisfy the demands from 10G to 100G interconnection. All of direct attach copper cables can meet the ever growing need to cost-effectively deliver more bandwidth, and can be customized to meet different requirements.

40G network is gradually being applied in today’s backbone transmission network, during which long distance transmission is required. 40G QSFP+ SR4 fiber optic transceiver is being widely applied for 40G transmission in short distances. Generally, 40G QSFP+ SR4, working on wavelength of 850 nm, can support 40G fiber optic transmission a distance up to 150 m over OM4 multimode optical fiber. Inserted in switch, QSFP+ SR4 module utilizes a MTP/MPO interface for dual way transmission. There are a lot of methods to connect QSFP+ SR4 transceivers with other devices for different applications, by using different connectivity products. In addition, the cabling for 40G is relatively more difficult than that of 10G network, which requires more cables and spaces. The following will introduce several high density QSFP+ SR4 transceiver cabling methods.

QSFP+ SR4 40G to 40G Applications

40G to 40G transmission is needed in a 40G fiber optic network. The following picture simply illustrates how 40G to 40G multimode transmission is being achieved by QSFP+ SR4 transceivers. Two QSFP+ SR4 modules are separately inserted in two 40G switches. Then the two transceiver are connected by a length of multimode MTP trunk cable. This is the simplest way to use QSFP+ SR4 transceiver.

In some cases, there are lot of 40G connections required at the same time and same places, which means the increasing of both cable count and cabling difficulty. For better cable management and higher density cabling, a 48-port 1U rack mount MTP fiber patch enclosure can be used as shown in the following picture. Up to four 12-port MTP fiber adapter panels can be deployed in this standard 1U rack mount enclosure. With the help of this 48-port MTP fiber enclosure, cable management for 40G connections could be easier.

QSFP+ SR4 40G to 10G Applications

QSFP+ SR4 is a parallel fiber optic transceiver which means it uses four fibers for transmitting and four fibers for receiving at the same time. The 40G fiber optic signal can be separated into four 10G signals to meet the 40G to 10G transferring requirements. The fiber optic cable count will be increased at the 10G distribution end. Usually a breakout MTP-8LC harness cable is used. For better cable management, a 1U 96-fiber enclosure is recommended, which includes four HD MTP cassettes transferring MTP front the 40G end to LC at the 10G end. Four 10G-SR SFP+ modules, inserted in 10G switch/ports, can be connected to the corresponding LC ports on this fiber enclosure to achieve the duplex transmission between 40G and 10G.

For higher cabling density, the above mentioned 48-port 1U rack mount MTP fiber patch enclosure is still being recommended, which can provide high density 40G MTP cabling environment. And additional MTP-8LC harness cables should be used for transferring signals between 40G and 10G (shown in the following picture).

Conclusion

Depending on its parallel transmission mode, QSFP+ SR4 modules can meet a variety of cabling applications with great flexibility. The above methods is just several commonly used ones, detailed cabling methods for QSFP+ SR4 modules are depended on the practical applications and cabling environments. Related products for the above mentioned methods are listed in the following tables. Kindly visit fiber-mart.COM or click the attached links for more details. You can also contact sales@fiber-mart.com for more information about 40G cabling.