“Multimode Fiber Optical fiber that supports propagation of multiple modes of light. Multimode fibers have a larger core diameter than single mode fibers. Typical multi-mode wavelengths are 850 and 1300 nanometers (nm); singlemode, at 1300 and 1500 nm. When specifying attenuation, it is important to note if it is nominal or average, room temperature, value or maximum over operating range.”