Compared with single-mode fiber, multimode fiber (MMF) is characterized by which statement?

Compared with single-mode fiber, multimode fiber (MMF) is characterized by which statement?

• A. Longer maximum transmission distance than single-mode
• B. A larger core size that supports multiple light modes
• C. More expensive transceivers
• D. Smaller core that supports fewer modes

Answer: (B)

Multimode fiber is defined by its larger core diameter, which allows multiple light paths (modes) to travel simultaneously. That bigger core, typically around 50 microns (and historically 62.5 microns) compared with about 8–10 microns for single-mode fiber, is what enables multiple modes to propagate. Because many modes exist, modal dispersion occurs, which broadens the signal as it travels and limits distance. That’s why MMF is used for shorter links, while single-mode fiber can carry signals over much longer distances with much less dispersion. So the statement that best describes MMF relative to single-mode is that it has a larger core size that supports multiple light modes. The other options don’t fit: MMF doesn’t offer longer maximum transmission distances than single-mode; it’s typically shorter. Transceivers for MMF are usually less expensive (not more). And MMF has a larger, not smaller, core that supports more modes, not fewer.

Multimode fiber is defined by its larger core diameter, which allows multiple light paths (modes) to travel simultaneously. That bigger core, typically around 50 microns (and historically 62.5 microns) compared with about 8–10 microns for single-mode fiber, is what enables multiple modes to propagate. Because many modes exist, modal dispersion occurs, which broadens the signal as it travels and limits distance. That’s why MMF is used for shorter links, while single-mode fiber can carry signals over much longer distances with much less dispersion.

So the statement that best describes MMF relative to single-mode is that it has a larger core size that supports multiple light modes. The other options don’t fit: MMF doesn’t offer longer maximum transmission distances than single-mode; it’s typically shorter. Transceivers for MMF are usually less expensive (not more). And MMF has a larger, not smaller, core that supports more modes, not fewer.