In daily weak current construction, it is often encountered when optical fibers need to be spliced. The editor lists several common problems in the process of splicing optical fibers. I hope it will help you a little.

1. There are bubbles or cracks in the contacts during welding

In this case, it may be that the fiber is not cut properly, such as the end face is inclined, has burrs or the end face is not clean, and the fiber needs to be cleaned before the fusion splicing operation; another case is that the anti-electric electrode is aging, and the electrode rod needs to be replaced.

2. The welding is too thick or the contact is thin

Too thick splicing and thickening of the joint are often caused by too much fiber feed and too fast pushing; the shrinking head and thinning of the splicing joint are generally caused by insufficient feeding amount and too strong discharge arc. All these problems need to adjust the parameters of arc protection and fiber feeding.

3. The loss after heat shrinkage is larger than that before heat shrinkage

This situation is because the optical fiber is polluted after stripping the protective jacket. When the heat shrinkable tube is shrunk after the fusion splicing, the residual contaminants (such as tiny sand particles) will press the optical fiber and cause the optical fiber to deform, so the fusion loss will increase. At this time, it is necessary to re-clean the fiber and re-splicing.

4. The coiled fiber causes the short fiber or the loss to increase

After the optical fiber is spliced, it should be handled with care when it is fixed in the splice box to ensure that the optical fiber is above the minimum bending radius. The splice 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:

① The quality of the fiber itself is not good;

②The cut surface of the optical fiber is not flat, resulting in poor fusion effect;

③ Improper force is applied when the personnel tray of the fusion joint is stuck in the slot.

6. Negative loss occurs when connecting

Negative loss occurs during connection, which is an upward trend on the test curve. It often occurs when a fiber with a large mode field diameter is connected to a small mode field diameter, because the ability of a fiber with a small mode field diameter to guide backscattered light is stronger than that of a fiber with a large mode field diameter. In this case, we should use the two-way test averaging method to calculate the true loss of the splice!