Fusion Splicers - the Most Precise and Accurate Method of Splicing Fiber Optic Cables

Splicing fiber optic cables is definitely not like splicing metal cables together. It's a very precise process best achieved using a fusion splicer. A fusion splicer connects two fiber optic cables together by melting or fusing them. In order to minimize potential optical loss or signal loss, optical fibers must be joined together absolutely perfectly.

Here's how the process works. The fiber cable ends are first fastened into an enclosure in the splicer in order to protect them during the fusing process. Next the ends are stripped of their coating. If an outer jacket is present it is also stripped. The next step involves a tool called a fiber cleaver. A fiber cleaver is used to cut the fibers in a way which leaves the ends of the cables perfectly smooth and flat. If the ends are not absolutely flat then a perfect splice will not occur. After cleaving the ends they are placed into holders in the splicer.

Now the splicer's motors align the cable ends together. Then the splicer generates a small spark at the gap between two electrodes. The reason for doing this is that you need to burn off any moisture or dust which is present. Dust or moisture can cause the splicing process to fail. After this step a much larger spark is generated which raises the temperature at the cable ends above the melting point of glass. This fuses the cable ends together. The location of the spark and the amount of electricity it contains are very carefully controlled. This precise control is necessary in order to ensure that the glass fiber and its cladding are not allowed to mix. If they mix together it results in optical loss.

After the cable ends are fused together the splicer injects light through the cladding on one side of the splice and measures the light leaking from the cladding on the other side. This measurement is taken to ascertain the quantity of splice loss. Splice loss is the amount of optical power lost at the splice point as a result of the splicing process. A splice loss of less than 0.1dB is routine when using a fusion splicer.

As a general rule the fiber ends are inspected before and after the splicing process. This is done using the splicer display screen which provides a magnified view of the splice area.

Fusion splicers are used extensively in the telecommunications industry as well as the computer networking industry. They are invaluable in insuring that fiber based network downtime is kept to a minimum.