Water is very harmful to fiber optic cables. If the fiber optic cable into the water, in the cold water icing expansion will be reported injury to the optical fiber, so the cable needs to be filled with grease, to prevent moisture from entering. When water enters the fiber optic cable, the chemicals and impurities in the water may also lead to corrosion and damage to the fiber optic cable.
Experiments have shown that the water is not into the fiber optic cable for a long time will make the fiber optic mourning increase, especially in the 1.55pm wavelength:
Optical fiber is afraid of water because: optical fiber is glass (Si04) silica-oxygen tetrahedral interconnected composition.
In the Si-O-Si network, oxygen atoms exist in the form of bridging oxygen.
However, in a water environment, the glass surface adsorption of water gas, slowly hydrolysis reaction, which led to the original network of a Si-O-Si one in the silicon oxygen bond breakage, bridging oxygen into non-bridging oxygen. As a result, glass cracks are caused, and the cracks grow.
Whether it is aquarium glass, window glass or fiber optic glass are afraid of water, the difference is that the aquarium glass, window glass are very thick, the thickness of 3mm, 5mm, l0mm, even if there is a 0.05mm crack does not affect the strength of the glass, the naked eye can not see the change. And fiber optic glass is different, fiber optic glass diameter is only 0.125mm, like a hairline as thick and thin, if there is 0.05mm cracks, fiber optic diameter is left 0.075mm, so the fiber is very easy to break the fiber.
Therefore, in order to ensure the normal operation and long-term reliability of optical fiber, optical fiber cables usually take a variety of waterproof measures, such as the use of waterproof materials to wrap the optical fiber, set up waterproof connectors and seals. In addition, during the installation and maintenance of fiber optic cables, care needs to be taken to avoid water contact and infiltration in order to protect the performance and life of the optical fiber.
