Fiber optic patch cords come in different thicknesses, primarily determined by the fiber core size and the cable jacket, which affect performance, distance, and application.

Core Size and Fiber Type

The core diameter is the main factor in fiber thickness. Single-mode fibers (OS1/OS2) typically have a core size of about 9 µm, allowing long-distance transmission with minimal signal loss, while multimode fibers (OM1/OM2/OM3/OM4/OM5) have larger cores, usually 50 µm or 62.5 µm, optimized for short-distance, high-bandwidth applications within data centers . The core size directly influences how light travels through the fiber and determines the effective transmission distance and bandwidth.

Jacket Thickness and Material

The outer jacket adds to the overall thickness of the patch cord and provides protection. Common jacket types include:

• PVC: Standard indoor use, flexible but not suitable for air ducts .
• Plenum (OFNP): Fire-resistant, safe for air ducts .
• Riser (OFNR): Used for vertical shafts between floors .
• LSZH (Low Smoke Zero Halogen): Emits minimal smoke and toxic gases when burned, common in Europe and high-safety areas . The jacket thickness varies depending on the material and intended environment, typically ranging from 2 mm to 3 mm for standard patch cords, with ruggedized or armored versions being thicker for extra protection .

Connector and Assembly Considerations

The connector type (LC, SC, ST, FC, MPO, etc.) does not significantly change the cable thickness but affects the overall assembly size and handling . Kevlar or aramid yarn is often included under the jacket to provide tensile strength without greatly increasing diameter .

Summary

Fiber optic patch cords vary in thickness due to core size, jacket material, and protective layers. Single-mode fibers are thinner in core but can have similar jacket thickness to multimode fibers. Multimode fibers have larger cores for higher bandwidth over short distances. Choosing the right thickness ensures optimal performance, durability, and compatibility with your network equipment .