How to cleave fiber optic cable?

How to cleave fiber optic cable?

In this article, we will have a look at how to cleave fiber optic. The process of cleaving a fiber is called fiber cleaving.

If you are a bit confused with the term "cleaving" then, it is a process of cutting or precisely an optical fiber for splicing or termination. Cleaving the fiber properly is important for getting good termination or optic splicing.

The process of fiber cutting is similar to cutting a glass plate. First, you scratch or score the surface and the apply stress to break the glass in a smooth manner just along the lines that were created by scratch. If done properly, the surface of cleaved fiber will be clean and perpendicular to the fiber's length and will have no protruding glass on any of the ends. The protruding glass is called a lip.

What is a cleaver?

It is a tool for holding fiber optic under low tension. It scores the surface at proper places and then a greater tension is applied until the fiber optic breaks. Good cleavers produce consistent results and are automatic. The only thing a user has to do is to clamp the optic fiber in the cleaver and operator the controls of cleaver. A cleaver can have less automation such that it would require manual force by the operator to break the fiber. This makes the cleaving process dependent on the technique of operator so the results are less predictable.

Another method that may be used for the removal of excessive fiber from a connector's end before polishing it, uses hand tool that is called scribe. It consists of a sharp and hard tip made of either diamond or carbide to manually scratch the fiber. After that, the fiber is pulled by the operator to break it. The results through this process can be adequate for polishing, however due to the process being manual, it is less predictable comparing it to a good cleaver. All you have to do is to ensure the breaking of fiber completely in front of ferrule of connector to polish it properly.


Importance of cleaving:

For two fibers to join, their ends must be mated. But the mating will not be proper if the fiber optics' ends aren't cleaved precisely. If there exists an angle on the cleaved ends, it will cause in a gap between cables and result in loss due to fusion splicing being uneven. If there is a lip or a protrusion, on any ends of fiber, then the two fibers will not connect well with each other. Due to these defects in the surface, known as mist or hackle, the light may get reflected or diffused. It will result in loss.

If you want a low splice loss, then cleaving the ends well is they key. This is a fact recognized by fusion splice manufacturers and their machines are equipped with precision cleavers. The cost of these cleavers can be high but it will enable the machine to make lossless splices.

If a splice or connector is pre-polished, then they may have poor yield and high loss. This is due to inexperienced installers that make poor cleaves by using cleavers that are inexpensive. If an installer is well-practiced and has a good cleaver, then the resulting splice or connector can have a high yield.

If you are to buy an inexpensive cleaver then you must be well aware about how to use it. Follow the instructions carefully and you can add something on your own while working to experiment with it. Inspect the cleaved fibers properly to check how good they are and continue to practice to make cleaves that are consistently good.


How to judge the results of cleaving?

There are different aspects of the quality of obtained cleaves. The relevance of these aspects depend on the application.

  • The surfaces you cleaved must precisely be perpendicular to the surface of fiber and must be smooth if you want to carry out fusion splicing. Fibers can't be fused properly if there's a protrusion.
  • For launching or extracting light from fiber ends without needing to bring fiber in contact with other solid parts.
  • A larger cleave angle is needed if the applications are sensitive to backward-reflections. The loss of return depends on the cleave angle exponentially.
  • The angle should be kept small if you want to exploit the Fresnel reflection of optic fiber.

Cleaving fibers with laser:

Devices consisting of carbon dioxide lasers can be helpful in preparing the ends of a fiber as an alternative solution to cleaving. It cannot be referred as cleaving, instead it can be called laser cutting. However, it is a common practice to call it laser cleaving because the results are similar to cleaving.

The results and reliability is better than mechanical cleaving.

Safety risks:

Small fiber scrapers are obtained by cleaving a fiber. They have ends that are extremely sharp. Such scraps can stick to fingers and may get transported to the naked eye. These scraps can penetrate into the skin and it is very hard to pull them out. These scraps must not be ingested. Before you lose these scraps, dispose them off quickly.

TM27 Cleaver:

TM27 Cleaver

TM27 is a high precision fiber optic cleaver/cutter. It is a 3 in 1 fiber holder.

It has 16 cleaving spots and 48000 cleaves blade life. It can cut 0.25, 0.9mm  fiber lengths.


So, if you are looking how to cleave fiber optic cable then this was a detailed description on the topic that might be helpful in making you understand.