Fiber Optics: Singlemode vs. Multimode
It is becoming apparent that almost everything is being replaced with fiber optics as an appropriate means of communication signal transmission. Fiber optics simply use light pulses to transmit information down lines of fiber. A transmitter, which is at one end of the system, is the place of origin for information coming onto the optical fiber lines. After the transmitter accepts coded electronic pulse information from copper wire, it translates the information into equivalently coded light pulses.
Using a lens, the light pulses are funneled into the fiber medium where they travel down the cable. On multi-mode fiber, the light is usually 850nm for shorter distances and 1,300nm for longer distances. On single-mode fiber, the light is usually 1,300nm for shorter distances and 1,500 for longer distances.
Single-mode fiber is a single stand of glass fiber, usually consisting of 2 fibers, with a diameter of 8.3 to 10 microns and has only one mode of transmission. Single-mode, having a relatively smaller diameter than multi-mode, carries higher bandwidth than multi-mode, but requires a light source with a narrow spectral width. Although single-mode fiber costs more than multi-mode, it gives you a higher transmission rate and up to 50 times more distance. The small core virtually eliminates any distortions that could result from overlapping pulses, providing the least signal interruption and the highest transmission speeds of any fiber optic type.
Multi-mode optical fiber has a slightly larger diameter, ranging from 50 to 100 microns. The most common size is of multi-mode fiber optic cable is 62.5 microns. Light waves are dispersed into multiple paths, or modes, as they travel the cables core. Unlike singlemode, multi-mode can become distorted at the receiving end, resulting in an unclear and incomplete data transmission during long cable runs.