Fiber Optic Cabling

Cabling that carries data as light pulses, offering long distance and immunity to electromagnetic interference.

Fiber optic cabling transmits data as pulses of light through a glass or plastic core, making it immune to electromagnetic interference and capable of far greater distances and bandwidth than copper. Single-mode fiber (SMF) uses a narrow core and a laser source to reach many kilometers, while multimode fiber (MMF) uses a wider core with LED or VCSEL sources for shorter campus runs. A common exam trap is confusing connectors with cable type: LC connectors are small-form-factor and dominate data centers, while SC connectors are larger and common in older runs. Neither connector determines single-mode versus multimode — that lives in the fiber and its transceiver.

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