On the Impact of Strong Electromagnetic Fields on Fiber-Optic Communication Lines

Results of physical simulation of the impact of lightning electromagnetic radiation on fiber-optic communication lines performed using a lightning current generator are presented. In the course of simulation of the lightning current, the first component of the lightning current was formed: a current pulse of the first reverse discharge with an amplitude of more than 190 kA and a front duration of 4 μs. A completely dielectric fiber-optic cable was located at different distances from the discharge gap or outside the screened room in which the lightning current generator was located. Linearly polarized radiation was used as a signal transmitted via a fiber-optic cable. The rotation of the plane of polarization was recorded by measuring the power of the transmitted signal. A rapid change in the state of polarization of the transmitted signal was revealed at the moment of discharge of the lightning-current generator. A surge in the optical radiation power was observed for a cable laid close to and at a distance from the discharge gap. The power of optical radiation transmitted through a cable laid outside the screened room practically did not change at the time of discharge. A hypothesis has been made that the electrical component of the electromagnetic field induced by a lightning discharge makes a more significant contribution to the rotation of the polarization plane than does magnetic component.