Author: Fiber-MART.COM

eShop of Fiber Optic Network, Fiber Cables & Tools

Proper Care of Polishing Fixtures for Optical Fiber Polishing Machines

In fiber optic cable assembly, the polishing process is perhaps the most critical step to assure high-quality assemblies that meet specifications. That’s why it’s important to select the right optical fiber polishing machine – and polishing fixtures – that meet your needs. Depending on your cable assembly house product offerings, it’s likely that you have several polishing fixtures to produce different connector styles.

The quality of the polishing fixtures (also called polishing plates or jigs) is extremely important to your company. Considering the high cost of production equipment and components, your company will want to maintain these tools to produce a high volume of products with minimal quality issues over the long run.

Proper maintenance of polishing fixtures is absolutely essential

Polishing fixtures for optical fiber polishing machines are built with high-precision machining equipment. Fixtures made of steel and aluminum can flex and warp over time, which will negatively impact your polishing process and product quality. On the other hand, polishing fixtures made of hardened stainless steel avoid this wear effect. However, hardened stainless steel contains more iron in the alloy, so this does increase the risk of rusting. This is a key reason why proper maintenance is so critical.

In addition, the most common fiber optic connectors (SC, LC, and E2000) are locked onto the polishing fixture with a plastic latch or clamp, which can wear over time if not properly cleaned. Poor cleaning techniques can also prevent proper locking. This can significantly impact the polishing machine’s functionality and, therefore, product quality.

Polishing fixtures are expensive – this is a bottom-line reason why proper maintenance is so important. With daily maintenance, you can use your polishing fixtures for a long time with no variation in the quality level of your fiber optic cable assemblies.

Follow these 8 steps to clean and maintain your polishing fixtures

Whether your company is just starting to manufacture fiber optic cable assemblies – or you have years of experience – we recommend you rigorously follow these guidelines to properly clean and maintain your polishing fixtures.

It’s better to clean every day for 5 minutes rather than clean once a week for 30 minutes. In fact, we recommend you integrate a cleaning procedure throughout the daily polishing process. Cleaning the fixtures should be a regular task – and a priority – in your polishing process.

Use distilled water, because it doesn’t contain abrasive minerals. Do not use tap water – regular drinking water is different all over the world. Your company’s tap water may contain iron minerals that tend to adhere to the polishing fixture. Also, do not use alcohol. At Fiber Optic Center, we recommend the Air Cleanse Cleaning Wand. This hand-held cleaning wand has an integrated pressurized fluid and filter system for a debris-free cleaning operation. You can use the wand to clean any brand of polishing machine and fixture. Click to read the datasheet for the Air Cleanse Cleaning Wand from Domaille Engineering.

The ferrule holes (and for MT style fixtures the ferrule slots, surrounding surfaces, and top clamps) can be cleaned using dental brushes and particle‐free, distilled or deionized water. Again, do not use alcohol. We recommend using a 1.25mm nylon brush (purple-handled brush) for fixtures with 1.25mm diameter ferrule holes. Use a 2.5mm nylon brush (blue-handled brush) for fixtures with 2.5mm diameter ferrule holes. Either one will work fine for MT style fixtures.

Clean the fixture while it’s still wet from the polishing process. This makes it easy to remove the polishing debris.

To clean areas where a brush can’t reach, use an ultrasonic bath. When using an ultrasonic bath, you must change the deionized water every day. Otherwise, debris could contaminate the polishing fixture. (Again, here is the link for the Air Cleanse Cleaning Wand datasheet.)

If you have a fixture with a cam-lock interface, pay special attention to the spring slits. These are very narrow and debris can easily build up, causing the metal to flex less and interfere with the spring functionality.

After cleaning the polishing fixture, it’s important to dry it thoroughly to avoid rusting. This is especially true for polishing fixtures made of hardened stainless steel.

Over time, your polishing results may change, and the reason could be directly related to natural wear of key interfaces of the polishing machine and fixture. The EZ-Check Precision Wear Gage Kit provides precise measurements for the polishing machine mandrel, fixture mounting hole, and ferrule holes. We recommend incorporating this wear gage kit into your process control system. Call Fiber Optic Center to determine whether this tool works with your polishing machine and fixture.

Considerations About Fiber Optic Cable Installation

It’s true that fiber optic cable, based on optical technology to carry information between two points, have become increasingly important in fiber optic systems. This cable is often attached with the same or different connectors on the ends to connect devices, for example, LC LC multimode patch cord (LCs on both ends). When used in premises, fiber optic cables can be used as backbone cabling in a standard structured cabling network, connecting network hardware in the computer room. And when applied in optimized fiber optic networks, they go directly to the work area with only passive connections in the links. They can be installed indoors or outdoors using several different installation processes. One of my recent blogs has talked about safety issues about fiber optic cable installation. Today, this article still focuses on its installation, but from other aspects, including the general guidelines, its pulling tension, bend radius, and so on.

When deployed outside, fiber optic cables may be direct buried, pulled or blown into conduit or innerduct, or installed aerially between poles. When used outside, they can be e installed in raceways, cable trays, placed in hangers, pulled into conduit or innerduct or blown though special ducts with compressed gas. The installation process depends on the nature of the installation and the type of cables being used.

Installation General Guidelines

First point to mention is that fiber optic cable is often custom-designed for the installation and the manufacturer may have specific instructions on its installation. So, it’s highly recommended to follow the cable manufacturer’s suggestions. Often, it’s necessary to check the cable length to make sure the cable being pulled is long enough for the run, so as to prevent having to splice fiber and provide special protection for the splices. Of course, it’s better to try to complete the installation in one pull. Prior to any installation, one should assess the route carefully to determine the methods of installation and obstacles that are likely to be encountered.

Pulling Tension

Fiber optic cable is designed to be pulled with much greater force than copper wire if pulled correctly, but excess stress may harm the fibers, potentially causing eventual failure. Cable manufacturers install special strength members, usually aramid yarn, for pulling. Fiber optic cable should only be pulled by these strength members. Any other method may put stress on the fibers and harm them. During installation, swivel pulling eyes should be used to attach the pulling rope or tape to the cable to prevent cable twisting during the pull.

Besides, cables should not be pulled by the jacket unless it is specifically approved by the cable manufacturers and an approved cable grip is used. Tight buffer cable can be pulled by the jacket in premises applications if a large (~40 cm, 8 in.) spool is used as a pulling mandrel. It’s right to wrap the cable around the spool 5 times and hold gently when pulling.

It’s ill-advised to exceed the maximum pulling tension rating. It’s suggested to consult the cable manufacturer and suppliers of conduit, innerduct, and cable lubricants for guidelines on tension ratings and lubricant use.

On long runs (up to approximately 3 miles or 5 kilometers), one should use proper lubricants and make sure they are compatible with the cable jacket. If possible, an automated puller can be used with tension control and/or a breakaway pulling eye. On very long runs (farther than approximately 2.5 miles or 4 kilometers), one should pull from the middle out to both ends or use an automated fiber puller at intermediate point(s) for a continuous pull.

Bend Radius

When there are no specific recommendations from the cable manufacturer, the cable should not be pulled over a bend radius smaller than twenty (20) times the cable diameter. And after completion of the pull, the cable should not have any bend radius smaller than ten times the cable diameter.

Twisting cable

It’s known that twisting the cable can stress the fibers, thus in no case should one twist the cable. (Tension on the cable and pulling ropes can cause twisting.)

Use a swivel pulling eye to connect the pull rope to the cable to prevent pulling tension causing twisting forces on the cable.

Roll the cable off the spool instead of spinning it off the spool end to prevent putting a twist in the cable for every turn on the spool.

When laying cable out for a long pull, use a “figure 8” on the ground to prevent twisting. The figure 8 puts a half twist in on one side of the 8 and takes it out on the other, preventing twists.

Conclusion

Fiber optic cables have been widely deployed for computer net- works (LANs), closed circuit TV (video), voice links (telephone, intercom, audio), building management, security or fire alarm systems, or any other communications link. With its installation in large scale, it’s of great importance to know some basic points on cable installation discussed in this text. As for the fiber optic cables chosen for project, you can try Fiberstore, whose cables are available in many types, like SC fiber optic cable, LC SC cable, MTP cable. All are test- and quality-assured, suitable for both indoor and outdoor installation.

Do You Know How to Save Fibers in Your Networks?

As we all know, in order to meet the increasing demand for higher bandwidth and faster transmission speed, more and more fiber optic cables have been put into use. However, as fiber infrastructures are getting more complicated, only adding numerous cables is no longer a feasible and economical option. Service providers and network managers are always seeking for more cost-effective ways to enhance network capacity. Then do you know how to save fibers in your network to achieve an economical cabling? Here may have the answer you want to know.

A Key Technology—CWDM

CWDM stands for Course Wave Division Multiplexing. It can combine or multiplex more than one wavelength over one fiber. The CWDM is limited to 16 wavelengths and is typically deployed at networks up to 80 km since optical amplifiers cannot be used due to the large spacing between channels. And it has a wide spectrum and accommodates eight channels. This wide spacing of channels allows for the use of moderately priced optics. Generally, CWDM is used for lower-cost, lower-capacity, shorter-distance applications where cost is an important decision factor.

A Critical Component—CWDM Mux/Demux

The most common use of CWDM Mux/Demux is to increase fiber networks capacity without at the expense of deploying more fiber cables, which service providers and network managers are seeking for. CWDM Mux/Demux modules are bidirectional optical multiplexers which enable several optical signals at different wavelengths to pass through a single fiber strand. It can combine up to 18 different wavelength signals coming from a single optical fiber to 18 separate optical fibers. It’s this feature that makes CWDM Mux/Demux a good choice for high bandwidth but low cost solution. Here are two common types of CWDM Mux/Demux.

CWDM Mux/Demux Over Dual Fiber

The CWDM Mux/Demux over dual fiber is a universal device capable of coming up to 18 optical signals into a fiber pair. It can support up to 18 CWDM wavelengths between ITU-T G.694.2 1270 nm to 1610 nm in 20 nm increments or ITU-T G.652 1270 nm and 1290 nm. This CWDM Mux/Demux has good performance and excellent environmental stability. And it is typically used with optical amplifiers.

CWDM Mux/Demux Over Single Fiber

The CWDM Mux/Demux over single fiber can multiplex up to 18 optical single fibers and support a brand architecture such as scalable point-to-point links to two fiber protected rings. It can multiplex several channels such as 2, 4, 5, 8, 9, 16 and 18 channels on a single fiber, data rates or protocols over single fiber optic link without interfering with each other. Besides, this CWDM Mux/Demux is simple to be installed and requires no configuration or maintenance.

Advantages of CWDM Over DWDM

Some people may have doubt that DWDM is also a good solution for expanding network capacity. Of course it does. However, comparing these two technologies—CWDM and DWDM, CWDM has more advantages. The main advantage of CWDM is the cost of the optics which is typically one third of the cost of the equivalent DWDM optics. CWDM devices are popular with low cost, less power, less precision and lower maintenance requirements. In terms of economic scale, not so many requirements need to exceed 80 wavelengths, which means that CWDM is easier to be accepted by many common customers.

Summary

CWDM Mux/Demux is a good solution for expanding network performance while keeping the cost low since you can send the same amount signals with fewer fibers. fiber-mart.COM offers a complete portfolio of CWDM Mux/Demux over dual fiber or signal fiber with package types of plastic ABS module cassette, 19” 1RU rack and LGX metal box. Welcome to enquire for more detailed information.

How to Easily Upgrade Your Network to 40G Ethernet

The increasing need for higher bandwidth and faster data transmission drives the evolution of network Ethernet. 40G Ethernet is gradually becoming commonplace in telecommunication networks, as 10G cannot satisfy the never-stopping longing for higher speed communication any more. Unlike 1G migrating to 10G, 10G migrating to 40G gets across a much larger span in terms of not only transmission data rate but also technologies. Thus, the deployment of 40G is much more complicated than that of 10G. Today, I’d like to introduce several indispensable components to help those who want to easily upgrade their network to 40G Ethernet.

QSFP+ Fiber Optic Transceiver

Fiber optic transceiver is a very basic component in today’s telecommunication network. It is composed of both a transmitter and a receiver that are arranged in parallel so that they can operate with their own circuity that enables each of them to handle transmission in both directions. There are different types of optical transceivers for different Ethernet networks, such as GBIC for 1G, SFP+ for 10G, CFP for 100G. As for 40G data transmission, QSFP+ (quad small form-factor plus) transceiver module is the most commonly used type.

QSFP+ transceiver (shown in picture below) is a compact, hot-pluggable transceiver, which is evolved from QSFP transceiver, used for high-speed data communications applications. It provides four channels of data in one pluggable interface, with each channel capable of transmitting data at 10Gbps and supporting a total of 40Gbps. The 40G QSFP+ transceiver offers customers high-density 40G connectivity option for data center, high-performance computing networks, enterprise core and distribution layers, and service provider transport applications.

High-Density MPO/MTP Cables

Unlike standard fiber patch cables with the maximum data rate of 10Gbps, a patch cord terminated with 12-fiber or 24-fiber MPO/MTP connectors is available for 40G, or even 100G Ethernet. MPO/MTP trunk cable and MPO/MTP harness cable are the two widely applied high-density fiber cables in upgrading network to 40G Ethernet.

MPO/MTP Trunk Cable—MPO/MTP trunk cable, terminated with MPO/MTP connectors at both end, are typically available with 12 to 144 fibers and create a permanent fiber links between panels in a structured environment. With plug and play architecture, MPO/MTP trunk cable greatly reduces the initial installation and ongoing maintenance costs. Generally, 12-fiber and 24-fiber MPO/MTP trunk cables are respectively commonly used types for 40G and 100G applications. Here is a 72-fiber MPO/MTP trunk cable with 6 MPO/MTP connectors at both ends.

MPO/MTP Harness Cable—MPO/MTP harness cable, also named MPO/MTP fan-out cable or MTP/MPO breakout cable, is terminated with a male/female MTP connector on one side and several duplex LC/SC connectors on the other side, providing a transmission from multi-fiber cables to individual fiber or duplex fiber connectors. Compared to normal LC fiber optic cable, these cables are designed for high density applications which require high performance and fast installation. MPO/MPO harness cables are ideal for interconnecting MPO/MTP cassettes, panels or backbone MPO/MTP assemblies with the active equipment, saving costly data center rack space and easing fiber management. The image below shows a 1m MTP-4LC SMM harness cable.

40G QSFP+ Cable Assemblies

40G QSFP+ cable is a cost-effective solution for 40G data center. It is a low-power alternative to optical QSFP+ system. 40G QSFP+ direct attach cable (DAC) and 40G QSFP+ active optical cable (AOC) are two types os 40G QSFP+ cables.

40G QSFP+ DAC—QSFP+ DAC is a copper 40 Gigabit Ethernet cable which comes in either an active or passive twinax cable assembly and connects directly into a QSFP+ housing. An active twinax cable has active electronic components in the QSFP+ housing, while the passive twinax cable is mainly just a straight “wire” and contains few components. Generally, twinax cables shorter than 5 meters are passive and those longer than 5 meters are active.

40G QSFP+ AOC—QSFP+ AOC is a cabling technology that accepts the same electrical inputs as a traditional copper cable, but uses optical fiber between the connectors. QSFP+ AOC uses electrical-to-optical conversion on the cable ends to improve speed and distance performance of the cable without sacrificing compatibility with standard electrical interfaces. The following picture shows a QSFP+ to 4SFP+ AOC and a QSFP+ to QSFP+ DAC.

Conclusion

To upgrade your network to 40G Ethernet, you should prepare components like QSFP+ transceivers, MPO/MTP fiber cables and QSFP+ cables, etc. All of these devices can be purchased in fiber-mart.COM. Just need a click, you can take all these components to home and upgrade to 40G Ethernet easily.

Fiber Optic Transceivers with CWDM Technology

CWDM (coarse wavelength division multiplexing) is the low-cost type of WDM technology, which is often used in metropolitan area network access networks. It is considered to be a flexible and economical solution to expand the existing network capacity without adding additional optical fibers. There are many devices deploying with CWDM technology used in telecommunication applications, like CWDM modules and CWDM Mux/Demux, to provide a cost-effective way for migrating to higher-rate infrastructures. This post will mainly introduce several fiber optic transceivers with CWDM technology.

Overview of CWDM Transceiver and Its Working Principle

CWDM transceiver is a hot-pluggable transceiver that combines with CWDM technology usually used to achieve connectivity between existing network equipment and CWDM Mux/Demux. This type of transceiver module can provide high-capacity bandwidth by carrying up to 16 channels on a single fiber in the spectrum grid from 1270 nm to 1610 nm with a 20 nm channel spacing, when used with CWDM Mux/Demux.

Similar to the working principle of prism, there is a multiplexer and a demultiplexer at the either end of the whole CWDM system. A multiplexer is at the transmitting end to combine several signals together, and a demultiplexer is at the receiving end to split the signals apart. The more detailed information can be see in the following image.

Several CWDM Transceiver Types

Actually, with the increasing need for CWDM technology in different applications, there are many types of fiber optic transceivers with CWDM technology, such as CWDM SFP, CWDM SFP+, CWDM XFP, CWDM X2, and CWDM XENPAK, etc. In the following part I will mainly introduce CWDM SFP, CWDM SFP+ and CWDM XFP.

CWDM SFP: CWDM SFP is hot-pluggable and transceiver component which is compliant with SFP MSA and IEEE 802.3 & ROHS. The transceiver uses a LC single-mode fiber to achieve data rates of 1G, 2G and 4G for the maximum link length of up to 200 km. You can connect the CWDM SFPs to CWDM passive optical system, add/drop multiplexer (OADM) modules or multiplexer and demultiplexer plug-in modules using single-mode fiber optic cables.

CWDM SFP+: CWDM SFP+ as shown below is based on the popular SFP form factor, which is an MSA standard build. It is designed for 10G Ethernet applications in data center, campus and metropolitan area access networks where require flexible and cost-effective systems. This type of CWDM module can reach a maximum speed of 11.25Gbps and is commonly used to support up to eight channels of 10G Ethernet over single-mode fiber at the wavelength including 1490 nm, 1510 nm, 1530 nm,1550 nm, 1570 nm, 1590 nm and 1610 nm.

CWDM XFP: CWDM XFP as shown in the image below, compatible with XFP MSA, is designed for single-mode fiber and operates at a nominal wavelength of CWDM technology, from 1270 nm to 1610 nm. CWDM XFP is mainly used for typical routers and switch line card applications.

Advantages of CWDM Transceiver

Cost-saving—As we have mentioned above, CWDM module combining with CWDM technology can share a single fiber with several optical connections, thus expanding the bandwidth of fiber and allowing multiple applications to run over the same resources, which saves more cost than using other types of optical transceivers. Besides, due to the broader channel spacing in CWDM, cheaper uncooled lasers are used in CWDM modules, giving them another cost advantage.

Increasing Network Capacity—By transmitting multiple data channels using separate optical wavelengths on the same optical fiber, CWDM modules can greatly increase network capacity. They reduce network equipment inventories, and eliminate the need to maintain extra units or devices with various fiber types for network repairs or upgrades. They can also enable the network to upgrade and to be in use over a longer time without replacing the whole network by providing interchangeable fiber connectors which can easily adapt to and modify any existing network.

Low Power-consumption—Another advantage of CWDM module is low power-consumption. CWDM lasers without thermoelectric cooler and temperature control function, it is possible to significantly reduce the power consumption. For example, a DWDM based module each laser is about 4 W power consumption, while the cooler CWDM module laser consumes only 0.5 W.

Summary

CWDM transceiver provides high speed and physical compactness that today’s networks require while delivering the deployment flexibility and inventory control that network administrators demand. fiber-mart.COM offers a wide range of CWDM modules, including the common used three types we have mentioned above, and the types we don’t discussed in detail, like CWDM X2, CWDM XENPAK, and CWDM GBIC. All of these modules are fully compatible with the original brand ones. You can come to fiber-mart.com for more detailed information.

Fiber Optic PC Connectors: Single-channel vs. Multi-channel

Over the past 30 years, fiber optic technology has spanned its commitment constantly with, even more, endeavors nowadays to meet the ever-increasing networking bandwidth for high-quality Internet applications. In these applications, fiber optic connectors, serving as mousetraps, are used to couple the source, receiver and other components to the fiber optic cable. Fiber optic connectors generally use either physical contact (PC) or expanded beam technology. This article mainly discusses PC connectors from single-channel and multi-channel aspects.

It’s necessary to figure out what PC connections are first.

What Are PC Connection?

A PC connection is accomplished by terminating the optical fiber into a precise ceramic ferrule. The tip of the ceramic ferrule is polished in a precise manner to ensure that light enters and exits at a known trajectory with little scattering or optical loss. In achieving PC connection, there are two requirements for a cleaved fiber end face for PC connection. One is that the fiber end face inclination is less than 0.6°, and the other is that there is no mist on the end face.

PC Connector Types

There are countless single-channel and multi-channel fiber optic PC connector types available for telecommunication and data communication industries.

Single-channel Connectors

PC connectors are characteristic of directly mating and polishing fibers by utilizing tight tolerance ferrules and alignment sleeves and/or mating pins. This ceramic-ferruled technology permits reliable optical performance, with several designs becoming widely used as industry standards. Typically, these connectors are single fiber solutions with plastic shells. FC and ST connectors are becoming less popular but are still used in instrumentation. LC and SC connectors are commonly used in the telecommunication industry.

As a push-pull connector, LC connector, licensed by Lucent Technologies, provides a pull-proof design and small size perfect for high-density applications. It’s available in simplex or duplex versions, widely used in 10Gigabit, 40Gigabit, and 100Gigabit applications. Like Cisco QSFP-40GE-LR4 transceiver, QSFP-40GE-LR4 listed on Fiber-mart.com establishes 40Gigabit Ethernet (GbE) links with this duplex LC connector for 10km maximum link length over single-mode fiber (SMF).

SC connector, developed by Nippon Telegraph and Telephone (NTT), is recommended in the TIA/EIA-568-A Standard for structured cabling. It’s also available in simplex or duplex versions, typically used in Analog CATV (Cable Television) and other telecoms applications including point to point and passive optical networking.

Multi-channel Connectors

Multi-channel connectors house multiple fiber optic termini in a precision insertion. The termini can be configured as a pin/socket combination or genderless. MTP/MPO connectors belong to PC multi-channel connector.

The US CONEC MTP is an MPO compatible connector that exhibits quick and reliable connections for up to 12 fibers in a very small form factor. Just like LC connector, 40G links are likely to deploy this kind of MPO-12 connector for high performance. Take Cisco QSFP-40G-CSR4 for example, this QSFP-40G-CSR4 transceiver sets up 40G links in 850nm multi-mode fiber (MMF), with MPO-12 as its connector.

Optical Performance

Both single-channel and multi-channel PC connectors have optical performance characterized by return loss. The return loss of the connector is a measurement of how much light is reflected back at the connector interface. It’s affected by alignment, contamination, and polishing. For example, if the mating faces of the two fibers are not parallel, some energy reflects back to the source. Additionally, contamination at the mating interface causes reflection and scattering of light. What’s more, a poor polish may create an end-gap separation or an end angle.

Featuring by the tightest tolerance ceramic ferrules and alignment sleeves, coupled with the highest quality termination and polishing procedures, PC connections are able to deliver unrivaled optical performance.

Conclusion

Fiber optic connectors make quick fiber connection and efficient light transmission possible, gaining more and more popularity among their users. Fiber-mart.com offers hundreds of fiber optic connectors, such as FC, D4, DIN, MU, the MTP/MPO ST, SC and LC, as well as their related optic modules (eg. QSFP-40GE-LR4 and QSFP-40G-CSR4 mentioned above). You can visit Fiber-mart.com for more information about fiber optic connectors.