Which type of fiber optic cable is typically used for short-distance applications, like within a building?

Multi-mode fiber is the correct choice for short-distance applications, like within a building, due to its design and performance characteristics. It has a larger core size than single-mode fiber, allowing multiple light modes to propagate simultaneously. This enables effective transmission over shorter distances, making it well-suited for applications such as connecting devices within the same building or campus, where the distances are typically less than 2 kilometers.

The structure of multi-mode fiber also supports lower-cost light sources like LEDs, which are effective over these shorter distances. This significantly reduces the overall cost of the installation while providing sufficient bandwidth for many applications such as video or data.

In contrast, single-mode fiber is generally used for long-distance applications because it can transmit data over much greater distances with lower attenuation and higher bandwidth, but it requires more expensive lasers as light sources. Coaxial cable and twisted pair cable, while used in some data and telecommunications settings, are not fiber optic solutions and do not leverage the benefits of light transmission, which include higher bandwidth and immunity to electromagnetic interference. Therefore, multi-mode fiber stands out as the optimal choice for short-distance networking tasks within a building.