What Is Dual Mode Fiber Optic Cable?

By Jennifer VanBaren

A fiber optic cable is a thin glass strand used for transmitting light. Fiber optic cables are used primarily by telephone companies and electric companies. They are typically either single mode or dual mode, also called multimode.


Single mode fiber optic cables are used for high speed and long distances; dual mode fiber optic cables are primarily used for short distances.


Dual mode fiber optic cables have a slightly bigger diameter than single mode. Dual mode generally uses two fibers instead of one and offers a high bandwidth. Dual mode cables are not used for long distances, over 3,000 feet, because the multiple light paths lead to distortion to the receiving party.


Dual mode fiber optic cables are made of glass and have diameters between 50 microns to 100 microns. Light is transferred through these cables using numerous paths. A single mode fiber optic contains a diameter between 8.3 microns to 10 microns and light is transferred via one path only.