When it comes to optical fibers, we often think of optical fiber fusion technology. Indeed, many people only have the basic knowledge of optical fiber fusion technology. The following will introduce the steps of optical fiber fusion technology for everyone.
What are the steps of optical fiber fusion technology
Optical fiber fusion is mainly divided into four steps: stripping, cutting, melting, and protecting.
The so-called stripping: refers to stripping the optical fiber core in the optical cable, which includes the outermost plastic layer, the middle steel wire, the plastic layer in the inner layer and the color paint layer on the surface of the optical fiber.
The so-called cutting: refers to cutting the end face of the stripped optical fiber to be spliced with a "cutter".
The so-called fusion: refers to the fusion of two optical fibers together in a "splicer".
The so-called protection: refers to the protection of the optical fiber connector that has been spliced with a "heat shrinkable tube".
Decomposition of specific steps of optical fiber fusion technology
Fiber end face preparation
The preparation of the fiber end face includes the steps of stripping, cleaning and cutting. A qualified fiber end face is a necessary condition for fusion splicing, and the quality of the end face directly affects the quality of fusion splicing.
(1) Stripping of the optical fiber coating
Proficient in the three-character stripping method of flat, steady and fast. "Flat" means to keep the fiber flat. The thumb and index finger of the left hand pinch the optical fiber to make it horizontal, and 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. "Stable" means that the fiber stripper should be held firmly. "Fast", that is, the fiber should be stripped quickly. The fiber stripper should be perpendicular to the fiber, tilted upward at a certain angle inward, and then lightly clamp the fiber with the jaws. The right hand will follow with force and push it out along the axis of the fiber. The whole process To be natural and smooth, in one go.
(2) Cleaning of bare fibers
Observe whether the coating layer of the stripped part of the fiber is completely stripped, if there is any residue, it should be stripped again. If there is a very small amount of coating that is not easy to peel off, you can use a cotton ball to dip an appropriate amount of alcohol, dipping it, and gradually wipe it off. A piece of cotton should be replaced in time after 2 to 3 times of use, and different parts and layers of the cotton should be used each time, which can not only improve the utilization rate of cotton, but also prevent the two pollution of fiber detection.
(3) Cutting of bare fibers
Cutting is the most critical part in the preparation of optical fiber endfaces. Precise and excellent cutters are the foundation, and strict and scientific operating specifications are the guarantee.
The choice of cutter There are two kinds of cutter, manual and electric. The former is simple to operate and has reliable performance. With the improvement of the operator's level, the cutting efficiency and quality can be greatly improved, and the bare fiber is required to be shorter, but the cutter has higher requirements on the ambient temperature difference. The latter has higher cutting quality and is suitable for operation in cold conditions in the field, but the operation is more complicated, the working speed is constant, and the bare fiber is required to be longer. Skilled operators should use a manual cutter for fast optical cable connection or emergency rescue at room temperature; on the contrary, for beginners or when working in colder conditions in the wild, use an electric cutter.
Operating Specifications Operators should be specially trained to master the essentials of action and operating specifications. First of all, clean the cutter and adjust the position of the cutter. The placement of the cutter should be stable. When cutting, the action should be natural and stable, not heavy or urgent, to avoid the occurrence of bad end faces such as broken fibers, bevels, burrs, and cracks. In addition, learn to "play the piano", reasonably distribute and use your right fingers, make them correspond and coordinate with the specific parts of the cutter, and improve the cutting speed and quality.
Beware of end-face contamination. The heat-shrinkable sleeve should be threaded before peeling, and it is strictly prohibited to pierce after the end-face is prepared. The cleaning, cutting and splicing time of bare fiber should be closely connected, and the interval should not be too long, especially the prepared end face should not be placed in the air. When moving, handle it with care to prevent it from rubbing against other objects. During the connection, according to the environment, the "V"-shaped groove, pressure plate and blade edge of the cutter should be cleaned to prevent end face pollution.
Fiber splicing
Optical fiber fusion splicing is the central part of the splicing work, so high-performance fusion splicer and scientific operation in the fusion splicing process are very necessary.
(1) Selection of fusion splicer
The selection of the fusion splicer should be equipped with fusion splicing equipment with suitable battery capacity and precision according to the requirements of the optical cable project.
(2) Parameter setting of fusion splicer
The key parameters such as the optimal pre-melting main melting current and time and the amount of fiber feeding are set according to the material and type of the optical fiber before fusion splicing. During the welding process, the "V"-shaped groove, electrodes, objective lens, welding chamber, etc. of the welding machine should also be cleaned in time. Observe whether there are air bubbles, too thin, too thick, virtual melting, separation and other undesirable phenomena in the welding at any time. Pay attention to the tracking and monitoring results of the OTDR. Timely analyze the causes of the above-mentioned undesirable phenomena and take corresponding improvement measures. If virtual fusion occurs many times, check whether the materials and models of the two optical fibers to be spliced match, whether the cutter and the fusion splicer are polluted by dust, and check the oxidation status of the electrodes. If there is no problem, the fusion current should be appropriately increased.
coil fiber
Coiling fiber is a technology and an art. The scientific method of coiling fiber can make the fiber layout reasonable, the additional loss is small, can withstand the test of time and harsh environment, and can avoid fiber breakage caused by extrusion.
(1) Disk fiber rules
The fiber is coiled along the loose tube or the branching direction of the optical cable. The former is suitable for all splicing projects; the latter is only suitable for the end of the main optical cable, and it is one in and multiple out. The branches are mostly small logarithmic cables. The rule is to reel the fiber once every time after splicing and heat shrinking one or several optical fibers in loose tubes, or optical fibers in a sub-technical direction optical cable. Advantages: It avoids the confusion of optical fibers between loose optical fiber tubes or between different branched optical cables, so that the layout is reasonable, easy to install, easy to disassemble, and more convenient for future maintenance.
(2) Method of coiling fiber
First the middle and then the two sides, that is, place the heat-shrinked sleeves one by one in the fixing grooves, and then deal with the remaining fibers on both sides. Advantages: It is beneficial to protect the optical fiber contacts and avoid possible damage caused by the coiled fiber. This method is often used when the optical fiber reserved disk space is small and the optical fiber is not easy to coil and fix.
According to the actual situation, a variety of graphic fiber coils are used. According to the length of the residual fiber and the size of the reserved disk space, coil it naturally according to the trend, do not pull it hard, and flexibly use circle, ellipse, "CC", "~" various shapes of coil fiber (note that R≥4cm), as large as possible Make maximum use of the reserved disk space and effectively reduce the additional loss caused by the disk fiber.
Assurance of optical cable connection quality
Strengthening the monitoring of OTDR is of great significance to ensure the splicing quality of optical fibers and reduce the additional loss caused by the coiled fibers and the damage that may be caused to the optical fibers by the sealing box. In the whole continuous work, the four monitoring procedures of OTDR must be strictly implemented:
(1) Real-time tracking and monitoring of each core fiber during the fusion process to check the quality of each fusion point;
(2) After each coiled fiber, conduct an example inspection on the coiled fiber to determine the additional loss caused by the coiled fiber;
(3) Before sealing the splicing box, conduct a unified test on all optical fibers to find out whether there is any leakage and whether the optical fibers and connectors are squeezed between the optical fiber reserved disks;
(4) After sealing the box, perform a final inspection on all optical fibers to check whether the sealing box has damage to the optical fibers.
The above are the steps of the optical fiber fusion technology and the decomposition of the specific steps of the optical fiber fusion technology. The continuous operation of the optical cable is a meticulous work, especially in the end face preparation, fusion, fiber coil and other links, requiring the operator to observe carefully and consider carefully. Operating Specifications. In short, in the work, it is necessary to cultivate a rigorous and meticulous work style, diligently summarize and think, in order to improve practical operation skills, reduce connection loss, and comprehensively improve the quality of optical cable connection.
