Fiber optic cable fusion splicing is a meticulous work, especially in the end face preparation, fusion splicing, coiling and other links. Fiber fusion splicing is to connect two-core fibers through a specific equipment fiber fusion splicer. 

1. Preparation before optical fiber fusion splicing

 First prepare fiber stripper, cutter, fusion splicer, heat-shrinkable tube, alcohol cotton and other necessary operating equipment, tools and necessary materials. Check whether the power supply of the fusion splicer is sufficient and whether all materials are complete .

2. Preparation of end face

The preparation of the fiber end face includes three steps: peeling, cleaning and cutting.

1). Stripping of optical fiber
Fiber stripping means stripping off the coating surface of the optical fiber.  "Ping" requires that the fiber must be level. The left thumb and index finger squeeze the optical fiber to make it horizontal. The exposed length is 5cm. The remaining fiber is naturally bent between the ring finger and the little finger to increase the strength and prevent slipping. "Fast" requires fast fiber stripping. The fiber stripper should be perpendicular to the fiber and tilted in the upper direction to a certain angle, and then gently clamp the right hand of the fiber with the jaws, then forcefully push it out along the fiber axis. 

First observe whether the coating layer of the stripped part of the fiber is completely stripped off. If there is any residue, it should be stripped off again. If there is a very small amount of coating that is not easy to peel off, use a cotton ball dipped in a suitable amount of alcohol, and gradually wipe off while dipping. When cleaning, tear the cotton into flat fan-shaped pieces, moisten it with a little alcohol, clamp the stripped fiber, and wipe it along the fiber axis without reciprocating motion. A piece of cotton should be replaced in time after being used 2 to 3 times, and different parts and layers of the cotton should be used each time.

First of all, clean the cutting knife and adjust the position of the cutting knife. The cutting knife should be placed steadily. When cutting, the movement should be natural and stable. At the same time, beware of end-face contamination. The heat shrinkable tubing should be inserted before peeling, and it is strictly prohibited to penetrate after the end surface is prepared. During splicing, clean the "V" groove, pressure plate, and blade of the cutter according to the environment. The cleaning, cutting and welding time of bare fiber should be closely connected, and the interval should not be too long.

The fusion splicing optical fiber should be equipped with a fusion splicing equipment with suitable battery capacity and precision, that is, a fusion splicer according to the requirements of the optical cable project. Because the welding machine is a high-tech, high-precision equipment, and the price is high, the selected welding machine must have excellent performance, stable operation, high welding quality, and be equipped with a dustproof windshield, large-capacity battery, etc., suitable for various Optical cable engineering .  Before fusion splicing, according to the material and type of the optical fiber, set the key parameters such as the optimal pre-melting main fusion current and time, and the amount of fiber input on the fusion splicer. During the welding process, the "V" groove, electrode, objective lens, welding chamber, etc. of the welding machine should be cleaned in time, and the welding should be observed at any time whether there are any defects such as bubbles, too thin, too thick, false melting, separation, etc., pay attention to the tracking and monitoring of the OTDR test instrument As a result, timely analyze the causes of the above-mentioned undesirable phenomena and take corresponding improvement measures. If false fusion occurs repeatedly, check whether the materials and models of the two fibers to be fused are matched, whether the cutter and the fusion splicer are contaminated by dust, and check the electrode oxidation status. If there is no problem, increase the fusion current appropriately. After ensuring that there is no problem with the quality of optical fiber splicing, heat shrink the loose tube to protect the optical cable at the splicing point, and place it in order and save it.

 When the fiber is coiled, it is generally carried out as a unit along the loose tube or the branch direction of the optical cable. After each fusion and heat shrinkage of one or several fibers in the loose tube or the optical fiber in a branch direction, the fiber is coiled once to avoid loosening of the fiber. The confusion of the optical fibers between the sleeves or the different branch cables makes it suitable for layout, easy to reel, easy to disassemble, and easy to maintain. It is also possible to reserve the heat-shrinkable tube placement unit in the tray as a unit of fiber, according to the number of heat-shrinkable tubes that can be placed in a small storage area in the reserved tray in the splicing box, thereby avoiding the same caused by different placement positions. Bundles of fibers are uneven, difficult to coil and fix, and even appear sharp bends and small loops.

During the entire splicing process, OTDR test instruments must be used to strengthen monitoring to ensure the splicing quality of the optical fiber, reduce the additional loss caused by the coil fiber and the damage that the box may cause to the optical fiber, and it must not be judged by the naked eye alone. Bad: (1) Real-time tracking and monitoring of each core fiber during the splicing process to check the quality of each splice point; (2) After each fiber reel, perform routine inspection on the fiber to determine the damage caused by the reel fiber Additional loss; (3) Perform a unified measurement on all optical fibers before sealing the box to find out whether there is any missing test and whether the reserved space for the optical fiber is squeezed on the optical fiber and the connector; (4) After the box is sealed, all optical fibers are finalized Monitor to check whether the sealed box damages the optical fiber.