Single-mode fiber is typically for ____ distances.

Single-mode fiber is typically for ____ distances.

• A. Shorter
• B. Longer
• C. Medium
• D. Undefined

Answer: (B)

Single-mode fiber is used for longer distances because its very small core forces light to propagate as a single path, greatly reducing modal dispersion. With fewer different paths for the light to take, pulses travel with less distortion, allowing higher bandwidth over long links and lower attenuation over distance. This makes single-mode fiber ideal for long-haul, backbone, and metro networks. For short distances, multimode fiber is often cheaper and simpler to connect, but it suffers more modal dispersion due to multiple propagation paths, which limits its useful distance.

Single-mode fiber is used for longer distances because its very small core forces light to propagate as a single path, greatly reducing modal dispersion. With fewer different paths for the light to take, pulses travel with less distortion, allowing higher bandwidth over long links and lower attenuation over distance. This makes single-mode fiber ideal for long-haul, backbone, and metro networks. For short distances, multimode fiber is often cheaper and simpler to connect, but it suffers more modal dispersion due to multiple propagation paths, which limits its useful distance.