What are the differences between Fiber Optic Cables
Last Updated: 01/31/2017
Cable used to transmit a light signal and consisting of a core of transparent glass encased in a cladding material (typically plastic) with a lower light refraction. A buffer material (type of material varies) surrounds and protects the cladding and core, and the assembly is encased in an overall jacket. Various other components may be present to add strength, protection, water blocking, etc.
Multi-mode fiber has a core size of 50 microns or 62.5 microns.
Single-mode fiber has a core size of 8.3 microns (sometimes rounded up to 9 microns in the nomenclature).
High speed data transfer within a network with less signal loss, greater bandwidth and distance than copper, and no susceptibility to many of the problems that plague copper cable (i.e. EMI/RFI, crosstalk).
Multi-mode: used for shorter cable lengths. Larger core allows multiple beams to travel down the core. The transceiver equipment is less expensive because it can use LED’s vs actual lasers. It is typically used as a backbone between floors and close buildings on campus.
Single-mode: used for long cable lengths. Smaller core uses a single beam that follows the core, thus being faster, brighter, providing higher bandwidth and allowing the longer cable lengths. Single-mode uses actual lasers and equipment is much more expensive. Typically used for extreme long distances, high speed, telco backbones, CATV networks, etc.
Fiber optic cable incorporates strengthening components within its construction (typically Kevlar aramid yarn) for pulling. The cable should be pulled by these components unless the cable is specifically designed for pulling by the jacket.
Pulling eyes should be attached to prevent the cable from twisting while pulling.
If maximum bend radius or pulling tension is exceeded and results in damage to the cable, it is assumed to be irreversible and the cabling is typically replaced. Repositioning or easing the tension does not necessarily undo the damage.
Cable manufacturers will have a specific maximum bend radius that must not be exceeded. In the absence of a specified max. the general rule is that the bend radius should be at least 20 times the cable diameter.
Do not twist the cable, which can stress the fibers.
Hook and loop fasteners are preferred for bundling and securing fiber optic cables. Cable ties may be used but should be hand-tightened only and should remain loose enough to move along the cable.
Cable with a plenum rated jacket has a minimum installation temperature of 32 degrees Fahrenheit. Installing below this temperature could result in the jacket developing cracks.
Related Industry Terms/Acronyms:
Panduit OptiCam Termination