Fiber optic patch cords are classified into several categories

Fiber optic patch cords are generally classified by fiber mode, connector type, and working mode, with single-mode and multimode being the primary fiber types.

Classification by Fiber Mode

Fiber optic patch cords are divided into single-mode and multimode types. Single-mode cables have a narrow core, allowing only one light path, which reduces attenuation and supports long-distance transmission, making them ideal for telecom and campus networks (yellow jacket) . Multimode cables have a wider core, supporting multiple light paths, higher bandwidth over short distances, and are commonly used in data centers and LANs. Multimode jackets are color-coded: OM1/OM2 (orange), OM3 (aqua), OM4 (violet), and OM5 (lime green) .

Classification by Connector Type

Patch cords are also classified by connector types, which ensure precise optical alignment. Common connectors include:

• LC: Small form factor, duplex, widely used in modern data centers .
• SC: Square snap-in connector, common in PON and enterprise networks .
• ST: Bayonet mount, legacy or industrial LANs .
• FC: Screw-on, suitable for high-vibration environments .
• MPO/MTP: Multi-fiber connectors for high-density parallel optics (8, 12, 24 fibers) .
• MU, MT-RJ, E2000: Specialized connectors for specific applications .

Classification by Working Mode

Fiber patch cords can be simplex (single fiber) or duplex (two fibers for bidirectional communication) . Simplex is used for one-way transmission, while duplex supports simultaneous send and receive operations.

Classification by Polish Type

The ferrule end-face polish affects return loss and signal quality:

• PC (Physical Contact): Slightly spherical, RL ~ -40 dB .
• UPC (Ultra Physical Contact): Refined polish, RL ~ -55 dB, common in digital applications .
• APC (Angled Physical Contact): 8° angle reduces back-reflection, ideal for high-performance networks .

Additional Considerations

Fiber patch cords may also vary by jacket material (PVC, LSZH, OFNP, OFNR) to meet fire safety and environmental requirements, and by strength members (Kevlar/aramid yarn) for durability . Choosing the right type ensures optimal network performance, low signal loss, and compatibility with equipment and installation environments. In summary, fiber optic patch cords are classified primarily by fiber mode, connector type, working mode, and polish type, with additional considerations for jacket material and durability, allowing tailored solutions for long-distance telecom, data centers, and enterprise networks .