A fiber-optic splicer is a mechanical device that is used to splice together two segments of fiber-optic cable. Splicing is needed if a cable run is too long for one piece of cable or if two different types of cable are being used. There are two methods of splicing fiber-optic cable: fusion and mechanical.
Fiber-optic cables are very small tubes of glass or special plastic. The inside of the tubes have a mirror finish that allows light to travel through them without being absorbed into the glass. Fiber-optic works better than copper cable for connecting computers to the Internet because copper absorbs some of the electrons passing through it. Photons, on the other hand, travel through fiber-optic cables with almost no loss of energy.
The best fiber-optic splicer is a fusion splicer, which welds two sections of cable together by causing an electric arc to pass between them, melting some of the glass. This joins the two sections into what is, for all practical purposes, a single piece of cable. The resulting joint, if made correctly, will absorb very little of the light traveling through it. Some types of fiber-optic joints must be made with a fusion splicer and can’t be made with a mechanical splicer.
The downside of a fusion fiber-optic splicer is that it is large and very expensive. In addition to the splicer, a precision cleaver, which also is expensive, is needed to make precise parallel ends on the sections to be joined. If the sections to be joined are not completely flat on the end, there can be a reflection problems and a loss of energy.
Some experience is required for users to consistently make good splices with a fiber-optic splicer. There is a danger of explosion and fire because of the electrical arc used to melt the ends. This is not an issue when repairing a buried outdoor cable that was severed, but using a fusion splicer down in a trench can be challenging.
A mechanical splice requires less expensive tools and less expertise. The connection loss is five to 10 times the connection loss of a fusion splicer, but in some situations, that does not matter. The two sections of fiber-optic cable must be cleaved, but the cleaving is not as critical as with a fusion splice because a self-contained assembly holds the pieces in precise alignment, and a gel is used to eliminate most of the light loss. The mechanical splice itself covers the joint and provides mechanical protection.