External Electromagnetic Influences upon Optical Cables

Abstract

This moment electric coupling is realized generally by means of optical fiber. Optical fiber cables are usually buried or suspended nearby earth surface. Electrical and magnetic fields of different sources can to exist in vicinity of optical fiber cable. Under influence of these fields the polarization plane of light rotates for some angle. As there is a small eccentricity of fiber, there are two main axes in a fiber, some birefringence springs up. If fiber cable has no metal in its design, the influences of transverse electrical field and of longitudinal magnetic field upon fiber stimulates turning of polarizations plane of lights in fiber. These effects are known as effects of Kerr and Faraday. Basic sources of external electromagnetic fields are lightning, high- altitude nuclear explosion and high-voltage lines. Lightning and high-altitude nuclear explosion can cause heavy current in metallic elements of cable and cable damage by gamma-rays. Exposure is of short overlooked depending on transmission type, but some times it can have severe effects.

Keywords

• Electromagnetic influence
• Lightning
• Polarizations plane rotation
• Gamma-rays