Fiber Optic Splicing
Optical fibers are extremely thin, transparent and flexible wires made of plastic or glass. Because of their main feature – transmitting light from one end to another – they have been found useful in a variety of modern technologies. Communication technologies are, probably, benefitting from them the most. Since optic fibers can transmit signals over longer distances and have broader bandwidths i.e. higher data rates, as compared to metal wires, they have become an irreplaceable part of modern communications.
Despite all of their advantages, just like with any other equipment, optic fibers do need occasional maintenance and repair. More specifically, it is often necessary to join two (or more) optic fibers into a single wire. This entire process is called splicing of optical fibers and it includes stripping, cleaning, cleaving and splicing. Let’s take a closer look at the final stage of the process.
There are two methods for splicing an optical fiber: mechanical and fusion. Mechanical splicing is a process which, ironically, does not involve actual splicing of the fibers but merely aligning them as precisely as possible and holding them in a self-contained assembly. Fusion splicing, on the other hand, does involve splicing (connecting) the fibers. Depending on the method, a mechanical or a fusion fiber optic splicer is used. In this article, we would like to focus on a more popular fusion splicing.
First of all, it is very important to follow the safety rules while splicing optical fibers with the fusion method, as the process involves working with high currents. It is prohibited to work with fusion fiber optic splicers in small enclosed spaces or spaces with explosive atmosphere (various gases, dusts or vapors when combined with air can form explosive environments). The best place to work with your device is above ground in a place with enough room.
One of the most important things to keep in mind is that the quality of your splice is directly related to how well the fibers are cleaved. Cleanliness is also very important, not just of the stripped fibers, but of the tools as well. Even the smallest dust particles that are not visible to a naked eye can cause huge problems. Make sure to use isopropyl alcohol and lint free wipes to clean the fibers until they start making a “squeaking” sound – this is a good indicator that they are clean. To sum up, in order for your splices to result in low light transmission loss (0.1-0.05 dB or even less), invest in a good fiber optic cleaver and make sure you frequently and thoroughly clean your tools (this does include the fiber optic splicer as well).
Most fusion fiber optic splicers are not that difficult to operate as they have several preset modes for splicing under different circumstances and do not require manual adjustments of the parameters. If there is a necessity to manually adjust the parameters, make sure you do this methodically and that your adjustments are quite minimal. Vey often the quality of the splice is not satisfactory because the fibers are not very clean. Checking whether they are clean should be the first step, and only after this you can proceed to adjusting the parameters. Fusion fiber optic splicers have two main parameters: current and time. In order to find the right set of parameters for your specific fiber make sure you adjust one parameter at a time. High current and low time can give the same result as low current and long time. Therefore, do not simultaneously increase the current and lower the time as there is a high probability that your splice will end up being the same as before the adjustments.
As mentioned previously, the actual process is not that difficult as the fiber optic splicer does almost everything automatically: after the fibers are placed, the device will analyze the cleaves (it will inform if their quality is not good and whether the fibers need to be cleaved again), prefuse and preheat them to remove any possible dirt, align them in the correct position and, finally, fuse the fibers together.
Afterwards, the fiber optic splicer will analyze the splice and evaluate the light transmission loss. If the result is too high, the device will inform that the fiber needs to be spliced again. If the result is satisfactory, all there is left to do is remove the fiber and protect the splice by putting a special protector on it. That’s it, the fiber is ready for use!