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

Single-mode fiber is specifically designed for long-distance communication due to its ability to carry light directly down the fiber without significant modal dispersion. Unlike multi-mode fiber, which has a larger core and allows multiple light modes to propagate, single-mode fiber has a much smaller core that restricts the light to a single path. This characteristic minimizes signal loss and allows for higher bandwidth over longer distances, making it ideal for telecommunications and data transmission applications where performance and distance are critical.

In addition, single-mode fiber operates effectively at wavelengths typically around 1310 nm and 1550 nm, which are optimal for long-distance transmission because they experience less attenuation and dispersion in the glass. This leads to an extended range of communication capabilities, often exceeding distances of several kilometers without the need for regeneration.

Thus, single-mode fiber's design and operational properties make it the preferred choice for applications requiring long-distance transmission capabilities in fiber optic networking.