Fusion or Mechanical: Which Is the Best Splicing Method?

When splicing together two lengths of fiber optic cabling, you have to choose between the two known methods - fusion splicing and mechanical splicing - which both essentially produce the same result - a secure connection between two formerly separate lengths of fiber.

However, how do you choose between them? Is one method better than the other? Well, in this article, we take a closer look at both, to provide some clarity on the subject. By reading to the end, you’ll know what the pros and cons are of each, how each connection is created and you’ll be in a better position to make a considered decision. 

So, without any further delay, let’s begin.

Defining Mechanical & Fusion Splicing

The ultimate goal of cable splicing is to create a secure connection between two or more sections of fiber in a way that allows the optical signal to pass through with minimal loss. As we mentioned already, both mechanical and fusion splicing achieve this goal, but they do so in very different ways. 

Fusion Splicing

Firstly, fusion splicing involves melting the two sections of fiber permanently together. This is achieved with an electrical device aptly known as a fusion splicer, and it’s something that not only melts the two parts together with an electric arc, but it is also able to align the fiber to create a good connection precisely.

Mechanical Splicing

One of the main differences with mechanical splicing is that it doesn’t permanently join the fibers together, instead of locking and aligning the pieces together with a screw mechanism. This method requires no heat or electricity at all.

The Fusion Splicing Steps

Figure 2: fusion splicer showing fiber positioning

With both mechanical and fusion splicing techniques, there are four distinct steps to the process. The first two steps for each are almost identical, but the final two are where the differences lie. 

Fusion Splicing Step 1 - Preparation

To prepare the fiber for splicing, you need to strip away the jacket or sheath that surrounds the internal glass fiber. You’ll be left with bare glass when you’re finished, which should then be cleaned with an alcoholic wipe.

Fusion Splicing Step 2 - Cleaving

The next step involves cleaving the fiber, which shouldn’t be confused with cutting. Cleaving means that the fiber should be lightly scored and then flexed until it naturally breaks. To create a sound connection, you need a good, clean, smooth cleave that’s perpendicular to the fiber it’s being connected to in the fusion splicer.