How to solve these six problems encountered in the process of optical fiber fusion splicing?
September 29 , 2021
1. There are bubbles or cracks in the contacts during welding This situation may be due to poor fiber cutting, such as the end face is inclined, burrs, or the end face is not clean, and the fiber needs to be cleaned before the splicing operation; there is also a situation that the electrical electrode is aging and the electrode rod needs to be replaced.
2. The welding is too thick or the contact point becomes thin Excessively thick splices and thicker contacts are often caused by too much fiber feed and too fast pushing; shrinkage of splices and thinner contacts are generally caused by insufficient feed and too strong discharge arc. These kinds of problems all need to adjust the arc protection parameters and the fiber feed parameters.
3. The loss after heat shrinkage is greater than that before heat shrinkage This is because the fiber is contaminated after the protective sheath is stripped off. When the heat shrinkable tube is shrunk after the fusion splicing, residual contaminants (such as tiny sand particles) will compress the fiber and cause the fiber to deform, so the splicing loss will increase. At this time, the optical fiber needs to be cleaned and spliced again.
4. Coiled fibers cause short fibers or increased loss After the optical fiber is spliced, when fixing it in the splice box, handle it gently to ensure that the optical fiber is above the minimum bending radius. The joint box should also be placed carefully to avoid being squeezed and bumped.
5. The mechanical strength of the weld is poor and it is easy to be broken There are many reasons for this situation: ① The quality of the fiber itself is not good; ②The cut surface of the optical fiber is not flat, resulting in poor splicing effect; ③Improper force was applied to the pallet of the shrink joint party.
6. Negative loss occurs during connection Negative loss during connection is an upward trend on the test curve. It often occurs when the fiber with a large mode field diameter is connected with a small mode field diameter, because the ability of the fiber with a small mode field diameter to guide backscattered light is stronger than that of the fiber with a large mode field diameter. In this case, we should use the two-way test average method to calculate the true loss of the splice!