Fiber optic termination is an important procedure to enable fiber cross connection and light wave signal distribution. Proper fiber optic termination will protect the fibers from dirt or damage while in use and prevent excessive loss of light, thus, making a network run more smoothly and efficiently. Generally, there are two ways to do fiber optic termination as shown in the following image. One is fiber optic connectors to mate two fibers for a temporary joint, while the other one is splicing to create a permanent joint between the two fibers. Both of these two termination methods must be of the right style, installed in a manner that provides low light loss and back reflection and protected against the expected environment, dirt or damage while in use. No area of fiber optics has been given greater attention than fiber optic termination. In the following part, we will illustrate how to do fiber optic termination with these two methods respectively.
Fiber Optic connectors are designed to be connected and disconnected many times without affecting the optical performance of the fiber circuit. Optical performance can be achieved by following the correct process for termination of the fiber circuit.
- Step 1: Prepare the fiber optic cable for termination, by stripping away the outer jacket, buffer, and cladding, and cutting away excess aramid yarn.
- Step 2: Using a fiber cleaver, score the fiber with a single, light touch. Do not press the cleaver more than once, in order to avoid additional scores on the fiber and eventually cause it to break.
- Step 3: Break the fiber by bending it together with the tongue of the cleaver.
- Step 4: Examine the fiber with a microscope designed to inspect fiber cleavers. Ensure that the cleaver is square and that there are no chips in the fiber.
- Step 5: Using the measuring card that is included in the tool kit, or using the scale on the cleaver, measure the bare fiber to ensure it is the proper length. If the bare fiber is too short, it will not reach the fiber inside the connector, and the connector will not work.
- Step 6: Clean the fiber with alcohol wipes that have at least 90% isopropyl alcohol content and lint-free material.
- Step 7: Carefully insert the bare fiber into the connector, crimp the connector onto the buffer.
Notes: 1. Before starting the termination , you should choose the right connectors, such as LC, SC, FC or ST connector, and the right polishing style including APC and UPC. 2. You should test periodically during the installation, rather than testing them all after the job is completed. Periodic testing can eliminate the possibility of repeating the same errors throughout the installation.
Splicing is only needed if the cable runs are 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. In addition, fiber optic splicing is also used to restore fiber optic cables when a buried cable is accidentally severed. There are two methods to splice fiber optic cables—fusion splicing and mechanical splicing. But the fusion splicing is more commonly used. There are main four steps to terminate fiber optic cable with fusion splicing. The folowing image shows how fusion splicing works.
- Step 1: The splicing process begins by preparing both fiber ends for fusion, so you need to strip the protective coating, jackets, tubes, strength members, etc, leaving only the bare fiber showing. The main concern here is to clean the cables.
- Step 2: Using a good fiber cleaver is essential to a successful fusion splice. The cleaved end-face must be mirror-smooth and perpendicular to the fiber axis to obtain a proper splice using the score-and-break method.
- Step 3: There are two steps within this step, alignment and heating. Alignment can be manual or automatic depending on what equipment you have. Once properly aligned the fusion splicer unit, then utilizes an electrical arc to melt the fibers, permanently welding the two fiber ends together.
- Step 4: Although a typical fusion splice will not break during normal handling as it has a tensile strength between 0.5 and 1.5 lbs, it still requires protection from excessive bending and pulling forces. With the help of heat shrink tubing, silicone gel and mechanical crimp protector, the splice can be protected from outside elements and breakage.
Both connector and splicing are good solutions to terminate fiber optic cable. Connectors can provide more easier and convenient way, while splicing is more professional and can keep the fibers connected with each other forever. The above text have offered detailed procedures of using these two methods. You can choose the appropriate one for your applications.