So, can lightning damage fiber optic cables? The short answer is yes, but it's not a straightforward answer. However, because fiber optic cable has strengthened core, especially the direct-buried fiber optic cable has armoring layer. Although the signals in fiber cables are optical signals, most of the outdoor optical cables using reinforced cores or armored optical cables are easy to get damaged under lightning because of the metal protective layer inside the cable. Induced Voltages: Electromagnetic induction from nearby. Fiber optic cables are made up of thin strands of glass or plastic fibers that transmit data as light signals. The result is a sudden release of energy that causes a distinctive bright flare, followed by a thunderclap. For example, it will not only affect all DWDM.