Used in fibre optic (FO) communications to transmit data using modulated light waves. Optical fibres have extremely high transmission rates of several GB/s.
Optical fibres are immune to interference and interception and have extremely low attenuation. Optical fibres are single mode or multimode.
In multimode fibres, signals are transmitted by several modes (light waves with varying runtimes), while single-mode fibres – as the name suggests – have only one mode given the extremely small diameter of their glass core.