The Two Major Methods of Fiber Optic Splicing

The Two Major Methods of Fiber Optic Splicing

Fiber optic slicing is an important process that involves the joining of two fiber optic cables together. It is usually carried out when a fiber cable isn’t long enough for the required run. Apart from that, splicing is also carried out to restore damaged or old fiber optic cables.

Fiber optic slicing is widely practiced in fields such as telecommunications, networking, and Local Area Networking (LAN).

Now, there are, generally speaking, two primary methods of splicing fiber optic cables. In this blog, we are going to explore both methods.

Fusion Splicing Method

Fusion splicing is all about connecting two or more optical fibers permanently. The fibers are welded together using an electric arc. This is the most commonly used splicing method for fiber optic cables.

So, why is it so popular? Well, it's because it has a high success rate, offers the most reliable joint between two fibers, and enjoys reduced reflectance.

Fusion Splicing is carried out using specific splicing machines. In general, four steps make up the bulk of the fusion splicing process.

The first step is to prepare the fiber ends for fusion. This involves stripping the coating, the strength members, the tubes, the jackets etc. In other words, the fiber must be left bare. Also, makes sure the cables are clean.

Next, you cleave the fiber. For this, you’ll need a fiber cleaver. The cleaver basically nicks the fiber and flexes it. This results in a clean break. The cleave end should be flat and kept perpendicular to the axis. This makes for a proper splice.

The third step is where you fuse the fiber. Here, you will first align the fiber ends within the splicer. Once that is done, you need to melt the fibers using an electric arc. Then, you can weld the fiber ends together permanently.

A proper fusion splice should boast a tensile strength of 1.5lbs at maximum and 0.5lbs at the minimum. In other words, it shouldn't break with standard uses. Even so, the spliced fiber optic needs some amount of protection to prevent the damage that arises from excessive pulling and bending, which does occur sometimes.

The protection is offered via silicone gel, mechanical crimp protectors, and heat shrink tubing. 

Mechanical Splicing Method

The next method is the automated splicing method. This method is best suited for quick and easy splicing. In a mechanical splice, you create a junction of optical fibers. The fibers are positioned and aligned with the help of a self-contained assembly.

As in the previous method, mechanical splicing can be divided into four steps. The first step is where you strip the fiber of jackets, tubes, strength members, etc. and leave it bare. The second step is where you cleave the fiber. Make sure you cut at right angles to the axis.

The third step is where the method starts to diverge. Instead of heating the fiber ends, you connect them within the mechanical splice unit. The index matching gel inside the unit will come in handy since it can couple the light from one fiber end to the other fiber end. Finally, to protect the spliced fibers, you will need to place them inside a splice tray and then, a splice closure.

The tubing is seal shrunk to prevent any further damage.