Today’s Basic Differences in Fusion-Splicing Machines


Because we’re involved in the daily supply of network cables and infrastructure we get to see shifting installation techniques and strategies many of you are using to get a network up and running as quickly and inexpensively as possible.

Tools that speed up installation have never been more popular with contractors. On a job, every minute counts. In a perfect world, the fastest terminations would also be the least expensive AND the highest performing. Fusion splicing of fiber optic cables may now be that prefect world. But the rule still applies:  you get what you pay for.

That’s why this article will explore the basic differences in the machines available today to splice fibers.

Remember, the objective when connecting any fiber together is to align the paths (cores) so that the maximum amount of light travels through them. The better the alignment, the better the cable performs its job.

Key definitions:

  • Fiber Core –The center of the fiber strand where the actual light is intended to travel with high refractive properties (today’s popular core sizes: 8.3um singlemode and 50um multimode)
  • Fiber Cladding –The layer(s) of material with low refractive properties that help keep the light traveling in the core. Cladding is usually 125um diameter.
  • Fiber Coating –Polymer or polymide coating is applied to the cladding to protect the fiber strand from damage. Coating diameter is commonly 250um, and can be colored for identification.
  • Buffer material – This coating is used for tight buffered cables – typically indoors. It is applied to a diameter of 900um, and is colored; providingmechanical protection of the strand inside termination equipment. It also aids in terminations by “beefing” up the size so it can be properly handled.
  • Concentricity – Yes, big word but really important. Being concentric in fiber means the various coatings all share the same exact center, and having the skill to produce concentric fiber strand pays off downstream in a big way.
  • Alignment – Ultimately, if we can align the core of two strands, light travels without disruption.

Now that we have defined the elements and the objective, we can discuss fusion options. We’re focusing on fusion options only; however, please keep  in mind that adhesive/polish and mechanical splicing are still valid alternatives.

An Active Core Alignment machine will actively (read: automatically) adjust the positioning motors so that the cores are perfectly aligned in the X, Y, & Z planes. Once aligned, a preheat/cleaning takes place followed by a series of arcs that fuse the two fibers together. This produces the highest performance connection in our industry. Once fused, the glass is nearly as strong at the fusion point as anywhere else on the strand… except if you bend it at the fuse site. That’s why we use fusion sleeves to keep that weld straight.

Active Clad Alignment machines will actively (read: automatically) adjust the positioning motors as well. The difference is that they align the cladding, not the core of each strand. These motors position the strand in perfect alignment of the cladding’s X, Y & Z planes just like the core alignment machine. Because this alignment is based on the outside of the strand, measurements are more easily obtained without the same expensive cameras and mirrors necessary for core alignment. Since this is simpler to accomplish manufacturers can offer these machines at lower prices, which is a good option if you are using new, high quality fiber cables.

If you want a machine that will fuse any type of glass, even the old stuff, go with a core alignment machine. You won’t be sorry you spent the extra money. They can literally fuse any glass out there.  Many core alignment machines offer several additional features to improve efficiencies on top of better core alignment: speed of the fusion, speed of the ovens that shrink the fusion sleeve in place, easy to use controls and even instructional onboarding videos.

However, if your world of terminations is exclusively new glass then a clad machine will do well for you.  The fiber optic manufacturers today produce glass that is extremely concentric. That means there’s little to no penalty in quality to align the cladding. If you spend most of your time inside the building, a machine like this can change your whole strategy on fiber. One project could put you in the fiber fusion business!

In addition, here are a few good sites to review:

No matter what machine you select, there are options that make it painless and fast. Use the form below to let us know how we can assist you.