Single mode cable is a single stand (most applications use 2 fibers) of glass fiber with a diameter of 8.3 to 10 microns that has one mode of transmission. Single mode fiber with a relatively narrow diameter, through which only one mode will propagate typically 1310 or 1550nm. Carries higher bandwidth than multimode fiber, but requires a light source with a narrow spectral width. Single mode fiber is used in many applications where data is sent at multi-frequency (WDM Wave-Division-Multiplexing) so only one cable is needed – (single-mode on one single fiber).
Single-mode fiber gives us a higher transmission rate and up to 50 times more distance than multimode, but it also costs more. Single-mode fiber has a much smaller core than multimode. The small core and single light-wave virtually eliminate any distortion that could result from overlapping light pulses, providing the least signal attenuation and the highest transmission speeds of any fiber cable type.
Single-mode optical fiber is an optical fiber in which only the lowest order bound mode can propagate at the wavelength of interest typically 1300 to 1320nm.
Multimode fiber optic cable is the another commonly used cables. Multi mode cable diameter is a little big, with a common diameters in the 50-to-100 micron range for the light carry component (in the United States, the most common size is 62.5um). In most applications, the use of multimode optical fiber, two fibers (WDM, usually without the use of multimode fiber). POF is a relatively new based on the plastic of the cable, the cable’s commitment is similar to that of the performance on the glass cable very short run, but at a lower cost.
Multimode fiber gives us a high bandwidth, high speed (10 to 100MBS -Gigabit to 275m to 2 kilometers), from the medium. Light waves are scattered into countless path or patterns, because they through the cable core is usually 850 or 850nm. Typical of the multimode optical fiber in the fiber in the fiber core diameter is 50, 62.5, and 100 microns. However, in the long cable (greater than 3000 feet 914.4m), the light of the multiple paths may lead to distortion of the signal at the receiving end, resulting in unclear, incomplete data transmission, so the designers now called for a new application using single mode fiber optic gigabit and beyond.
Singlemode fiber has a lower power loss characteristic than multimode fiber, which means light can travel longer distances through it than it can through multimode fiber. Not surprising, the optics required to drive singlemode fiber are more expensive. Both singlemode and modern multimode fiber can handle 10G speeds. The most important thing to consider is the distance requirement. Within a data center, it’s typical to use multimode which can get you 300-400 meters. If you have very long runs or are connecting over longer distance, single mode can get you 10km, 40km, 80km, and even farther – you just need to use the appropriate optic for the distance required, and again, the prices go up accordingly. Moreover, they are not compatible either, so you can’t mix multimode and singlemode fiber between two endpoints.