The Trouble with Mismatched Fibers

摘要

Gone are the days when all fiber optic cables were the same. Most building cables had 62.5/125 micron multimode fibers for LANs or security systems, while outside plant cables were all single-mode fiber. For some time, we have been encouraging people to install hy-brid cables with both multimode fibers for today and single-mode fibers for the future. In the last few years, fiber manufacturers have been offering "laser-rated" multi-mode fibers (see related column in the June 2003 issue) that have a 50-micron core, smaller than the 62.5 micron core of fibers normally installed. The incompatibility of the core sizes has created a new set of problems for contractors and installers working on installations that have more than one type of fiber.