Instruction manual

Euphonix FT730 FiberTran Fiberoptic Extender Operation Manual

Single Mode vs. Multimode Fiber Optic Cable

In optical fiber technology, multimode fiber is optical fiber that is designed to carry mul-

tiple light rays (modes) concurrently. Each mode is carried at a slightly different reflection

angle within the optical fiber core. Multimode fiber transmission is used for relatively

short distances (less than 6500 ft/2000 m) because the modes tend to disperse over longer

lengths (modal dispersion). For distances longer than 6500 ft (2000 m), single mode fiber

(sometimes called monomode) fiber is used. Multimode fiber has a typical core diameter

of 50–100 µm with a refractive index that is graded or stepped. It allows the use of inex-

pensive LED light sources, and connector alignment and coupling is less critical than for

single mode fiber. This translates into lower connection and electronics costs and conse-

quently lower overall system costs. The FT730 uses 62.5/125 µm multimode fiber with

ST connectors.