What type of fiber optic cable is typically used for long-distance communication?

Single-mode fiber is the correct choice for long-distance communication due to its design, which allows light to travel through a single pathway or core. This minimizes modal dispersion, which can distort signals when light travels through multiple paths, as is the case with multi-mode fiber.

Single-mode fiber typically has a smaller core diameter, usually around 8 to 10 microns, which means there is less opportunity for light to bounce around within the fiber. This characteristic enables the transmission of data over much longer distances, often exceeding 50 kilometers (31 miles), without significant loss of signal quality.

In contrast, multi-mode fiber, with a larger core diameter, is well-suited for shorter distances because it can support multiple light modes, which can lead to dispersion and signal degradation over longer lengths. Plastic fiber, while flexible and easy to install, is primarily used for short-range applications due to its higher attenuation compared to glass fibers, resulting in shorter transmission distances. Loose-tube fiber refers more to the construction method of the cable rather than the type of core used, and while it can accommodate either single-mode or multi-mode fibers, it is not inherently designed for long-distance communication.

Thus, single-mode fiber is specifically engineered for optimal performance in long-range