Which of these fiber optical cables can transmit light the greatest distance?

Single-mode step index fiber is designed specifically for long-distance communication. It allows light to travel directly down a single path, minimizing modal dispersion that occurs in multimode fibers. The core of single-mode fibers is much smaller than that of multimode fibers, usually around 8 to 10 micrometers in diameter, which enables it to maintain a single light path to transmit data over extended distances without significant loss of signal quality.

In contrast, multimode fibers, such as both multi-mode step index and multi-mode graded index fibers, have larger cores and support multiple light paths or modes. While they can carry more data simultaneously, their performance degrades more quickly over distance due to modal dispersion, which causes different light modes to arrive at different times and lead to signal distortion. This limits their effective range to a few hundred meters, depending on the specific setup and conditions.

Coaxial cable is primarily used for transmitting electrical signals rather than light and does not compete with optical fiber for distance capabilities. Its design is optimal for specific telecommunications applications but not for the high-bandwidth and long-distance signal transmission that fiber optics provide. Thus, when considering which type of fiber optical cable can transmit light the greatest distance, single-mode step index fiber stands out as the best