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Fiber Termination and Connection

Why Hire A Professional Cabling Contractor for Fiber?

After the bulk fiber cables have been installed throughout your building, the ends are just going to be cut off with bare fibers hanging out, and possibly a service loop.  Your cabling contractor may have installed those bulk cables and neglected to attach proper ends.  To terminate the fiber cables, you need to attach a connector to each fiber cable strand.  Before you can connect them to your equipment, you may need an LC connector on each fiber.  This is no easy task, and requires specialized tools and skills.  There are four types of connectors to choose from, depending upon the equipment in your data center. There is LC, SC, MTP/MPO, ST and FC.  The LC connector is the most common.  Most GBIC's use this kind.  Schedule a walk thru and bid today!

Fiber Termination And Connection

Fiber Optic Cable Cut Away

Terminating fiber optic cables involves the process of connecting the fine glass fiber strands to various components or devices, allowing for data transmission through light signals.  You may also have to splice fibers together at some point. Professional cabling installers usually have the tools and skills to do this properly.  If done incorrectly, there will be optical losses and tx/rx errors.  There are several methods of splice connecting fiber optic cables, but the two most common ones are:

1. Mechanical Splicing:

Mechanical splicing is a technique that aligns and connects the fiber ends using mechanical devices without the need for fiber fusion or fiber welding. Professional cabling installers usually have a kit with cable cleaver and a polishing wheel. Here's how it is typically done:

a. Preparing the Fiber: The first step is to clean and cleave (cut) the fiber ends to ensure a smooth and flat surface. Then cut back some of the insulation to expose the bare glass fiber and its glass cladding.  If you are very careful with with the cut and cleave, you will have a nice flat surface at the end of your cut fiber. The cladding will also be perfectly aligned with the fiber. 

b. Fiber Alignment: The fibers are placed in a mechanical splice device that holds them precisely aligned for optimal light transmission.

c. Index Matching Gel: An index-matching gel or fluid is applied between the fiber ends. This gel reduces signal loss and reflections at the splice point.

d. Splice Protection: A protective sleeve or housing is placed over the spliced fibers to safeguard them from dust, moisture, and mechanical damage.

Mechanical splicing is suitable for temporary or quick connections but is less robust and less efficient than fusion splicing.  It is often enough for most terminations.

2. Fusion Splicing:

Fusion splicing is a more permanent and precise method that involves fusing the fiber ends together using heat. This method is used with bulk cables and pre-made fiber pigtails.  Professional cabling installers usually have heat fusion tool for this task. This is how it's done:

a. Preparing the Fiber: The fiber ends are cleaned, stripped of their protective coatings, and cleaved to create smooth and flat end faces.  A length of bare fiber is exposed.

b. Fiber Alignment: The fibers are precisely aligned using a fusion splicer, ensuring minimum signal loss at the splice point.

c. Fusion: High heat is applied to the fiber ends, melting them together to form a continuous connection. This creates a low-loss joint with minimal reflectance.

d. Splice Protection: A protective sleeve or enclosure, usually made of heat-shrinkable material, is placed over the fusion splice to provide mechanical protection and maintain alignment.

Fusion splicing is commonly used in permanent installations, such as telecom networks, because of its superior performance and reliability.  Both mechanical and fusion splicing have their applications depending on the specific requirements of the installation and the desired performance level. For most critical and long-term applications, fusion splicing is preferred due to its lower insertion loss and higher stability.

Single Mode vs MultiMode

Customers always ask which is better?

single mode vs multi mode

How Do We Connect and Terminate Fiber Optic Cable?

Connect and Terminate Fiber Optic Cable - A Buyers Guide

Engineering a building cable design includes several important steps. The first step is to install a proper fiber termination box at each end.  If your cabling contractor just left a service loop, we recommend a termination box to mount and organize all of the termination ends. The best fiber boxes can accomodate multiple fiber cores, and have an organizer for service loops. 

Three Ways to Connect Fibers

There are three methods to connecting or terminating fiber cables in a data center: adhesive connection with field polishing, mechanical connectors and no polishing, or fusion splicing using pigtail assemblies. 

Field Polish with Adhesive Terminations

Adhesive connectors are a very common option in structured cable environments. The first step is to cleave the cable carefully, peeling back the insultion, extract the fiber, then polish the exposed fiber end with a very fine grit paper. Finally a 1 or 2 part epoxy adhesive is injected into the connector, and the fiber is inserted. An accelerator compound can be used to cure the adhesive more rapidly.

Adhesive terminations are the least expensive option. However, they require lots of precise skill and an eye for detail, so labor costs are a consideration. The Telecommunications Industry Association (TIA) has tightened its requirements single-mode return loss (reflectance), at 0.35 dB. Meeting those requirements becomes much more challenging with field polish connections. With enterprise networks moving to higher speeds, return loss is now more of a concern than ever. Minimizing return loss requires precise polishing procedures and an eye for detail, or choosing a factory polished connector such as mechanical terminations.

Pre-Polished Style Connectors
A much easier and faster way to attach a connector onto a fiber strand is using pre-polished connectors, so the fiber technician does not have to polish the fiber end. Polishing is usually where a lot of the labor, skill, and time occurs.  Terminating these pre-polished connectors typically requires less skill because the connectors are polished at the factory. Pre-polished connectors are sometimes referred to as “field termination connectors,” because they are used to make quick repairs or terminations out in the field.

Looking at the image on the right, you can see the small pre-polished piece of fiber already in the connector shown in blue. To terminate, the technician just needs to strip and clean the fiber strand to a specific length set by the manufacturer and insert it into the rear of the connector until it touches the piece of pre-polished fiber where it meets the index matching gel inside the connector. The index matching gel is a liquid material used to reduce signal reflections where two fibers meet.   At this point, depending upon the design of the pre-polished connector, you will just need to make a light crimp or twisting of the connector to lock the fiber in place for extended use. This completes the termination.

Factory Polish with Mechanical Connections

Factory polishing is usually an option with factory made pre-cut lengths of cable. If your building was wired with pre-made cables, then this is the easiest method. We have not seen too many professional fiber installs done this way.  If your data center used bulk cables, there is always an option to combine those with fiber pigtails. 

Fusion Splicing with Fiber Optic Pigtails

this is another option that uses factory made sections of fiber pigtails that have a factory made end and a bare fiber on the other.  The glass fibers are essentially welded together, then protected with a sleeve. This method will result in professionally made LC connectors on the ends of your fibers.

fiber termination box
Fiber Pigtails
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