Which type of fiber optic cable is designed for long-distance communication?

Single-mode fibers are specifically designed for long-distance communication due to their ability to transmit light directly down the center of the fiber with minimal loss. This type of fiber has a very small core diameter, typically around 8-10 micrometers, which allows only one mode of light to propagate. As a result, single-mode fibers can achieve longer transmission distances and higher bandwidths compared to other types of fiber optic cables.

The construction of single-mode fibers enables them to minimize modal dispersion, a phenomenon where different light modes travel at varied speeds leading to signal degradation over long distances. By using a single mode, the signal remains coherent and retains its quality over extensive lengths, making these fibers ideal for telecommunications and internet backbones that require long-haul connectivity.

In contrast, multi-mode fibers, with their larger core size (about 50 or 62.5 micrometers), support multiple light paths or modes, which can lead to increased modal dispersion and limit their effective transmission distance compared to single-mode fibers. Plastic fibers are generally less effective for long-distance communications due to higher attenuation rates and limited bandwidth capacity. Hybrid fibers combine characteristics of different fibers but are not specifically tailored for long-distance communication.