Which type of fiber optic cable is generally used for long-range communication?

Single mode fiber is used for long-range communication due to its design, which allows a single light mode to propagate through the core of the fiber. This type of fiber has a smaller core diameter, typically around 9 microns, which significantly reduces modal dispersion—an effect that occurs when different light modes travel at different speeds, potentially causing signal distortion over distances.

Because single mode fiber minimizes this dispersion, it can support higher bandwidths and transmit data over greater distances without signal loss or degradation, often exceeding several kilometers. This characteristic makes it ideal for telecommunications and internet backbone applications, where long-distance data transmission is crucial.

In contrast, multimode fiber, while useful for shorter distances and high data rates within local areas, suffers from modal dispersion when used for long-range applications due to its larger core—around 50 to 62.5 microns. This results in limitations on the distance data can travel without significant signal distortion.

Coaxial fiber and copper fiber are not appropriate terms in this context. Coaxial cable is typically used for RF signals and cable television distribution, and copper cables are used for electrical signaling, neither of which are designed for fiber optic communication or used in long-range data transmission scenarios.

Thus, single mode fiber is the