Used in fiber optic (FO) communications to transmit data using modulated light waves. Optical fibers have extremely high transmission rates of several GB/s.

Optical fibers are immune to interference and interception and have extremely low attenuation. Optical fibers are single mode or multimode.

In multimode fibers, signals are transmitted by several modes (light waves with varying runtimes), while single-mode fibers – as the name suggests – have only one mode given the extremely small diameter of their glass core.