Introduction to Buying Fiber Optic Patch Cords 1. Singlemode, Multimode, or Mode Conditioning Note:
Mode is a single electromagnetic field pattern that travels in fiber. Singlemode
is an optical fiber with a small core (2-9 microns) that supports one mode. The core/cladding size (e.g. 8.3/125) is stamped on the cable jacket, which is traditionally yellow. Singlemode is commonly used for high speed, long distance links.
Multimode
is an optical fiber with a core (25-200 microns) that supports several modes. The core/cladding size, commonly 62.5/125 or 50/125, is stamped on the cable jacket which is traditionally orange. Check equipment requirements or cable jacket to determine which core/cladding size you need. Multimode is used for lower speed, short distance links.
Mode Conditioning
is specific to Gigabit Ethernet applications. It eliminates multiple signals caused by differential mode delay effects, which would otherwise limit the cable distance lengths. Singlemode
, multimode, or mode conditioning cables are not interchangeable; if unsure check equipment requirements.
2. Simplex or Duplex Simplex
cable has a single fiber. Duplex cable has two fibers usually in zipcord (side by side) style. 3. Connectors Commonly used connectors are ST, SC, LC, MT-RJ, FC, ESCON,
FDDI(MIC), and VF45. Others are available. 4. Jacket Available jacket types are OFNR (PVC) Riser rated or OFNP Plenum rated. Local fire codes will specify the required type based on
the application. Short runs within a single room usually use a general purpose OFNR rated jacket. Longer runs through air ducts, and other air handling spaces usually require a plenum rated
jacket. If unsure check with your local Fire Marshall. 5. Pulleye Option A pulleye is an "easy pull" ring that is attached to the end of the cable to prevent damage during
installation. During installation the pulling force is redirected to the body of the cable instead of the core or connectors. This reduces the stress, and therefore damage, to the fibers. The
pulleye may be removed and reused. |
