By LUCAS MAYS, AFL -- Mass fusion splicing 12 fiber ribbons has long been an accepted and relatively unchanged process with little variation in application. You worked with either twelve 250µm coated fibers in an encapsulated ribbon, or twelve 250µm loose fibers bonded together with an adhesive to form a ribbon, also known as ribbonizing. A few years ago, the industry encountered a paradigm shift in fiber cable when the new collapsible ribbon technology hit the market. These ribbons are not held together by a surrounding encapsulation, but rather, staggered, intermittent bond points between fibers which provide long sections void of bonding material. This design allows the ribbon to fold on itself like loose fiber, while naturally resting in a horizontal side-by-side orientation like a conventional ribbon.
The combination of loose fiber and traditional ribbon attributes that these ribbons possess provide numerous customer advantages, such as increased packing density, smaller physical footprint, less material and lighter overall weight. The traditional ribbon characteristics mean this technology is inherently mass fusion splicing compatible, reducing install time and labor costs. Collapsible ribbons presented a few challenges from a splicing perspective, but these were only seen by the field technicians working with the products. Fortunately, for standard 250µm fibers, these issues were overcome by various splicing manufacturers via enhanced fiber holders. However, this technology is no longer the most recent development in fiber cable.
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Splicing Challenges with 200µm Fibers
Today, we’re experiencing another paradigm shift in cable and splicing technology with the introduction of 200µm coated fibers in the market. These smaller fibers are readily found in loose fiber cables, and compared to a standard 250µm loose fiber cables, the positives are unmet by any significant negatives from the customer’s viewpoint. The only real disadvantage is that currently most 200µm fiber applications can only be spliced one fiber at a time. The reason for single fiber splicing is that when looking at the fiber the difference is minute. The untouched fiber has shrunk by 50µm, and when the coating is stripped away, it is still 125µm glass.
However, if a technician wants to ribbonize these 200µm loose fibers for mass fusion splicing, the simplicity is lost. This type of splicing is not possible with standard equipment. Here’s why:
As you can see, the 200µm fibers will not naturally fall into all 12 V-grooves like traditional 250µm fibers. The reason being is that this 50µm reduction in diameter also reduces the fiber pitch. Pitch is the spacing between two successive corresponding points, for example, the spacing from tooth to tooth in a comb. In our case, pitch refers to the spacing between adjacent fiber cores. As a result of this diameter and pitch change, the 12 fiber ribbon width has shrunken significantly enough to prevent fibers from aligning with their respective V-groove. In order to mass fusion splice these fibers, separate solutions are needed.
Special 200µm V-groove splicers have been developed to accommodate this change in pitch, but this only allows you to splice to other 200µm fibers at a 200µm pitch. Ergo, if you only need to splice 200µm loose fibers to 200µm loose fibers, this special splicer along with a 200µm ribbonizing tool will solve your issues. However, some telecom customers currently have need for splicing 200µm loose fibers to 250µm ribbons. In the data center world, collapsible and encapsulated ribbons are being deployed with 200µm fibers, and in some cases, will need to be spliced to existing 250µm ribbons. So, if you want to broaden your portfolio to meet these needs, new tools are required to efficiently handle these varying splicing applications.
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Squeezing 250µm fibers into the same width as 200µm fibers is impossible, so your only option is to expand the 200µm ribbon pitch to match the pitch of a 250µm ribbon. This matching of fiber pitch is the ultimate goal to achieve versatile splicing in every application. Although, achieving this goal is not the same for every 200µm ribbon because each different ribbon type requires a different solution. To further complicate matters, each manufacturer's collapsible ribbons has a slightly different bond structure, meaning that achieving the increased 250µm pitch currently requires OEM dependent solutions for this ribbon type specifically. Since multiple solutions are needed to achieve the same goal, there exist applications which currently have no solution.
Know Your Options Today
As time goes on, splicer and cable manufacturers will adapt, compromise and work towards solutions. Ideally, the solutions will cross manufacturing boundaries, reducing the amount of equipment required to splice the various cables. Regardless, with these technologies still in their infancy, the processes, tools and methods for dealing with them are continually changing. The end results are still some time away, so knowing what you will be working with and asking about the current solutions ahead of time is key.
The important takeaway here is a ribbon is no longer just another ribbon. Before splicing any 200µm ribbon, ask these three questions:
1. Who is the manufacturer of the ribbons I’m dealing with?
2. What types of ribbon am I splicing?
3. What splicing equipment do I have available to me?
These questions will point you in the right direction in providing you the tools needed to splice in your application. The next step is to contact your local AFL representative who will put you in touch with our splicing experts to get you the rest of the way. So if you’re ever in this situation, don’t hesitate to pick up the phone and give us a call.
LUCAS MAYS is an Applications Engineer for field fusion splicers and accessories at AFL. He has previous optics industry experience both in the field as a splicer/installer and as an engineer working in R&D and product development. He earned a Bachelor of Science in Physics from the University of Louisville where he focused in optical sciences, driving his enthusiasm for his work at AFL.