When Do We Need Fiber Optic Splicing

When we want two fibers or fiber optic cables joint together, there are two method come to our head, installing a fiber optic connectors at the end of the optical fibers, or splicing the two optical fibers. Fiber optic cable splicing is a method that creates a permanent joint for two fibers, while fiber connector installation is used for temporary connections. There are two options for fiber optic splicing: Fiber optic cable fusion splicing and mechanical splicing. Both methods provide much lower insert loss than fiber optic connectors.

Common application for splicing is jointing cables in long outside plant cable runs where the length of the run requires more than one cable. Splicing is generally used to terminate singlemode fibers by splicing preterminated pigtails onto each fiber. It can be also used to mix numbers of different types of fiber cables like connecting a 48 fiber cables to six 8 fiber cables going to different places.

Fusion splicing provides a maximum insertion loss of 0.1 which is less than 0.5dB of mechanical splicing. Fusion splicer are available in two types that splice a single fiber or a ribbon of 12 fibers at one time. Almost all singlemode splices are fusion spliced. Mechanical splicing is most used for temporary restoration and for multimode splicing. Fusion splices are so good today that splice points may not be detectable in OTDR traces.

Fusion Splicing Process
Fusion splices are made by welding two fibers together by an electric arc of the fusion splicing machine. It can be not done in the enclosed space for safety reasons. It is suggested to done the job above the ground in a truck or trailer for a clean environment for splicing.

Fusion splicing needs the help of a special equipments which is fusion splicer to perform the splicing process. Main steps are aligning the two fibers precisely and generate a small electric arc to melt the fibers and weld them together.Splicing machine can do one fiber at a time while mass fusion splicer can do all 12 fibers in a ribbon at once.

Preparing fibers: The first step for fusion splicing is to strip, clean & cleave the fibers to be spliced. Stripping the primary buffer coating to expose the proper length of bare fiber with the fiber stripper. Clean the fiber with appropriate wipes, what you need is the fiber optic cleaning kit, Cleave the fiber using the directions appropriate to the fiber cleaver being used. Place each fiber into the guides in the fusion splicing machine and clamp it in place.

Running the splicer program: Choose the proper program according to the fiber type being spliced. The splicer would show the fibers being spliced on a video screen. The fiber ends will be inspected for proper cleavers and bad ones will be rejected for a second time cleaving. The fibers will be moved into position, prefused to remove any dirt on the fiber ends and preheat the fibers for splicing. The fibers will be aligned using the core alignment method used on that splicer. Then the fibers will be fused by an automatic arc cycle that heats them in an electric arc and feeds the
fibers together at a controlled rate.

Ribbon fusion splicing: Each ribbon is stripped, cleaved and spliced as a unit. Special tools are needed to strip the fiber ribbon, usually heating it first, then cleave all fibers at once. Many tools place the ribbon in a carrier that supports and aligns it through stripping, cleaving and splicing. Consult both cable and splicer manufacturers to ensure you have the proper directions.

Fusion splicing pigtail is another typical application for fiber optic splicing. By this method, a fiber optic patch cord is cut into two pigtails with connectors attached. The fibers are cleaved and welded together with a fusion splicer, which is considered to be the fastest and highest-quality method of fiber connector installation.

How Much Do You Know 40 Gigabit QSFP+ Transceiver

QSFP+ Module (Quad Small Form-factor Pluggable Plus) is a transceiver interfaces a network device motherboard (for a switch, router, media converter or similar device) to a fiber optic cable, widely used for data communications applications. It is a industry format jointly developed and supported by many network component vendors. QSFP is also the IEEE standard connector for the emerging 40GbE standard. Like SFP+, QSFP supports both copper and optical cabling solutions.

Features and Benefits:
● Support for 40GBASE Ethernet
● Hot-swappable input/output device that plugs into a 40-Gigabit Ethernet QSFP+ Cisco switch port
● Flexibility of interface choice
● Interoperable with other IEEE-compliant 40GBASE interfaces available in various form factors
● Support for “pay-as-you-populate” model
● Support for the Cisco quality identification (ID) feature which enables a Cisco switch to identify whether the module is certified and tested by Cisco.

The QSFP+ transceiver link length for either 40 Gigabit Ethernet or high density 10 Gigabit Ethernet application is up to 100 m using OM3 fiber or 150 m using OM4 fiber. These modules are designed to operate over multimode fiber systems using a nominal wavelength of 850nm. The electrical interface uses a 38 contact edge type connector. The optical interface uses an 8 or 12 fiber MTP (MPO) connector.

The 40G QSFP+ transceiver module is a hot-swappable, integrates 4 independent 10 gigabit per second data lanes in each direction to provide 40Gbps aggregate bandwidth. 40GBASE QSFP+ modules offer customers a wide variety of high-density 40 Gigabit Ethernet connectivity options for data center, high-performance computing networks, enterprise core and distribution layers, and service provider transport applications. The QSFP+ transceiver module connects the electrical circuitry of the system with either a copper or an optical external network. The transceiver is used primarily in short reach applications in switches, routers, and data center equipment where it provides higher density than SFP+ modules.

The QSFP specification supports Ethernet, Fiber Channel, InfiniBand and SONET/SDH standards with different data rate options. QSFP+ transceivers are designed to support Serial Attached SCSI, 40G Ethernet, 20G/40G Infiniband, and other communications standards. QSFP modules increase the port-density by nearly 3x when compared to SFP module. The QSFP transceiver include 40GBASE-SR4 and 40GBASE-LR4 for different applications.

QSFP-40G-SR4 Module supports link lengths of 100m and 150m respectively on laser-optimized OM3 and OM4 multimode fiber cables. It primarily enables high-bandwidth 40G optical links over ribbon fiber cables terminated with multi-fiber connectors, and could also be used along with ribbon to duplex fiber breakout cables for connectivity to four 10GBASE-SR optical interfaces.

Fiberstore offers the best QSFP modules. All these QSFP+ Modules are Cisco, Juniper, IBM and HP compatible! The QSFP transceivers are great a solution for multi-lane data communication and interconnect applications. In addition to 40Gbps Ethernet interconnects, it can be used in datacom/telecom switch, and router connections, as well as data aggregation and backplane applications. Also you can have a wide selection of other transceivers at Fiberstore.com, including xfp transceivers, CFP modules, sfp transceivers and so on.

What is a Punch Down Tool

A punch down tool is commonly used for the termination works in the copper network. Copper networks are most built by the twisted-pair cables like the Cat5, Cat5e, Cat6 and some newer standard Ethernet cables. These Ethernet cables usually need to be terminated with the keystone jacks, cross-connect blocks or patch panels. The punch down tools can be also called a punchdown tool or a Krone punch down tool, which is a small hand tool used by the telecommunication and network technicians. It is used to terminate the Ethernet cables by inserting the cables wires into the insulation-displacement connectors (IDC) on the punch down blocks, patch panels, keystone modules, and surface mount of boxes.

IDC is a little knife blade with a V-shaped gap or slit between them. In the working process, the punch down tool punches down and force the Ethernet twisted-pair cable conductor into the V-shaped gap. Then the IDC connector makes contact by cutting through, or displacing, the insulations around a single conductor inside a twisted-pair cable.

Most punch down tools are of the impact type, consisting of a handle, an internal spring mechanism, and a removable slotted blade. A punch-down tool is really just a handle with a special blade that fits a particular IDC.

what is a punch down tool

To accommodate different connector types, there are punch down tools with 66, 110, BIX and krone blades. Different blades are used depending on whether you are terminating 110 blocks or 66-blocks. The 66-block is mostly used in cross-connect blocks for voice cross-connects. The 110-block is now generic in usage and is a newer design by AT&T. 110 Block is most used for data network, although it is not absolutely so. Though the blades for each type are pretty different, most punch down tools on the market today can accept both types.

Substitute for a Punch Down Tool
The process of punching down a wire properly takes a considerable amount of force. You could just use a small flat-blade screwdriver as a substitute for a punch down tool. It is vital that you should take care no to break the thin wire before it makes contact with the desired slot.

Needle-nose pliers
Needle-nose pliers are also a viable option to replace a punch-down tool for occasional use. If you can find a small electronics set of pliers, it would often include a thin, bent-nose tool that aids in reaching behind challenging angles to push the wire between its slots.

Spring-loaded Nail Sets
A spring-loaded nail set is a standard nail set that incorporates a spring much like a small door spring to allow it to be snapped to generate force in a tight spot. In a time of need, you can grind it down to a flat blade than you can apply a similar force to a jack.

Tool-less Jacks
You can purchase slightly more expensive Ethernet jacks at any home store which utilize a tool-less design. In this design, the eight wires of an Ethernet cable are “grabbed” by a jaw-like interface and snapped and locked shut.

To do to the punching down the with the substitute above can be a good choice when you don’t have a punchdown tool on you hand. Buy it may be hard for an unpracticed man to control the force to the wires with the substitutes. By using the punch down tool helps you in applying the right amount of force in the right direction and assures a firm connection. FiberStore supply 110 punch down tool, Krone punch down tool and many other fiber optic tester and tools with competitive price.

Typical Designs for Fiber Optic Cables

As Fiber to the Home (FTTH) becomes more and more common, the term of fiber optic cable is no longer a strange noun for us. Let review it, a fiber optic cable is a most popular type of network cables that contains strands of glass fibers inside an insulated casing, which is in fact a assembly of optical fibers, the strength members and the cable jacket. Compare with the copper cables, fiber optic cables carry the communication signals by pulses of light rather than the electric. Due to the high capacity and less susceptible to electrical interference, fiber cables are widely used for the fiber optic telecommunication networks.

The optical fiber cables come in many different designs to fit for different environment and application areas. Choosing the right designed fiber cables is essential for your networking jobs.

Loose Tube and Tight Buffer Cables
Loose tuber and tight buffer are two typical designs of the fiber optic cables. Loose tuber fiber cables are used for the outside plant applications, in the Loose Tuber fiber cables, the fibers are placed loosely within a large plastic tube. Usually there are 6-12 fibers placed in the single loose tube. These tubes are filled with a gel or water absorbent powder to protect them from moisture and physical stresses. Loose tube fiber cables are commonly used for underground installations, lashed or self-supporting aerial installations, and other outside plant applications.
Tight Buffer cable designs are used for inside plant application. The fibers inside coated with a buffer coating, with an outside diameter of 900um. Tight buffer cable has two typical constructions with come in breakout design and distribution design.

Ribbon and Aerial Cables
Except for the loose tube and tight buffer cables, there are also ribbon design and aerial design fiber cables. A ribbon cable is a cable with many conducting wires or fibers running parallel to each other on the same flat plane, ribbon cables offer the highest fiber density relative to cable size, maximize use of pathway and spaces, and facilitate ease of termination., which make the ribbon fiber cables the beat choice for deployment in campus, building, and data-center backbone applications where fiber counts more than 24 are required. The ribbon cable can be used in Local area network (LAN) campus and building backbones as well as datacenter backbones.

aerial cable

An aerial cable is an insulated cables usually containing all conductors required for optical transmission system or telecommunication line, which is suspended between utility poles. Aerial cables can be lashed to a messenger or another cable (common in CATV) or have metal or aramid strength members to make them self supporting. Figure 8 self supporting Aerial Cable consists of an optical fiber cable core and integrated stranded steel messenger, used for campus-type environments, aerial links self-support or ducted underground service for long runs between buildings.

According the fiber numbers needed for the fiber optic cables, there are also Single-fiber cables and multi-fiber cables. When selecting a cable design for indoor or outdoor use, it is important that you should know what kind of fiber cable designs that you need. You can have a composite cable including copper conductors for signals or power, contact several professional fiber optic cable OEM manufacturers such as FiberStore. Give them the specification, they will evaluate your requirements and make suggestions for you.

The key physical parameters of fiber optic link

After the installation of fiber optic cabling system, it is needed to test the link transmission characteristics, including several most important test projects like link attenuation characteristics, connector insertion loss, return loss, etc. Following is a brief introduction of the measurements of the key physical parameters during the fiber optic cabling process.

The key physical parameters of fiber optic link:

1. Attenuation is the light power reduction in the fiber optic transmission.
2. Calculation of total attenuation of the fiber optic network: fiber LOSS is the ratio of the Power out of the fiber output end and the Power in of launched into the fiber.
3. The loss is proportional to the length of the fiber, so the total attenuation not only means the loss of fiber itself, but also reflects the length of the fiber.
4. Cable loss factor (α): In order to reflect the characteristics of the fiber attenuation, we introduce the concept of cable loss factor.
5. Attenuation measurements: As the fiber connected to the fiber optic light source and optical power meter will unavoidable take additional losses. Field test must carry on the test reference point setting (zero set). There are several methods for testing the reference point, these methods are mainly based on the link test object selection, in the fiber optic cabling system, since the length of the fiber itself is usually not long, so the test method will pay more attention to the connector and measurement of fiber optic patch cords, the method is more important.

Return Loss
The reflection loss, also known as return loss, refers to the backward reflection light relative to the ratio of the input number of decibels at the fiber optic connector, the return loss is larger the better, in order to reduce the reflection effect of light on the fiber light source and system.

The methods to improve return loss, try to use the fiber end surface is processed into spherical or oblique spherical is an effective way.

Insertion loss
Insertion loss is light signal in the optical fiber after through the connector, the output optical power relative to the input optical power ratio in decibels.
Insertion loss is smaller the better.
The insertion loss measuring method is the same with measuring method of attenuation.

In a word, to complete the measurement of an optical loss, a calibrated optical light source and a standard optical power meter is indispensable.