Fiber splicing involves joining two fiber optic cables together to establish an optical connection between two individual optical fibers. Fiber optic splicing typically results in lower light loss and back reflection than termination.
Splicing is needed if the cable runs too long for one straight pull or you need to mix a number of different types of cables (like bringing a 48 fiber cable in and splicing it to six 8 fiber cables). And of course, we use splices to repair damaged optical fibers during installation, accident, or stress. After the number one problem of outside plant cables, a dig-up and cut of a buried cable, usually referred to as “backhoe fade” for obvious reasons. System design may require that fiber connections have specific optical properties (low loss) that are met only by fiber-splicing. System designers generally require fiber splicing whenever repeated connection or disconnection is unnecessary or unwanted.
Fusion Splicing & Mechanical Splicing
Splices are “permanent” connections between two fibers. There are two common methods used to join optical fiber cables –Fusion Splicing & Mechanical Splicing, and the choice is usually based on cost or location. Most splicing is on long haul outside plant SM cables, not multimode LANs, so if you do outside plant SM jobs, you will want to learn how to fusion splice. If you do mostly MM LANs, you may never see a splice.
Fusion splicing is the act of joining two optical fibers end-to-end using heat. The goal is to fuse the two fibers together in such a way that light passing through the fibers is not scattered or reflected back by the splice, and so that the splice and the region surrounding it are almost as strong as the virgin fiber itself.
The principle of fusion splicing is that the two bare fiber ends (with coatings removed) are fused together under the influence of heat. More precisely, the fiber ends are initially brought in close contact, with a small gap in between. After heating them for a short while such that the surfaces melt, they are pushed together, such that the ends fuse together. In fusion splicing, splice loss is a direct function of the angles and quality of the two fiber-end faces. When doing fusion fiber optic splicing, usually people need Heat Shrink Tube splice protect sleeves to protect the fiber splices after the work is done.
Mechanical Splicing is a fiber splice where mechanical fixtures and materials perform fiber alignment and connection. Mechanical splicing is an optical junction where the fibers are precisely aligned and held in place by a self-contained assembly, not a permanent bond. This method aligns the two fiber ends to a common centerline, aligning their cores so the light can pass from one fiber to another. Mechanical fiber optic splicing is used for a quick repair and when only a small number of splices are required, its average cost for a single fiber optic splicing is high.
As for the performance of each splicing method, the decision is often based on what industry you are working in. Fusion splicing produces lower loss and less back reflection than mechanical splicing. Fusion splices are used primarily with single mode fiber where as Mechanical splices work with both single and multi mode fiber. The equipment to perform fusion splicing, named fusion splicer, is commercially available with a wide range of models.