The difference between single-mode fiber and multimode fiber:
Single mode fiber: capable of transmitting only one mode of signal wave. Single mode optical fibers, as they only propagate along a straight line without reflection, do not have mode dispersion, making their transmission frequency band very wide, making them suitable for backbone, large capacity, and long-distance systems. Using light-emitting diodes or lasers as light sources, using two wavelengths: 1310nm and 1550nm. The center glass core of a single mode fiber optic is very thin (usually with a core diameter of 9 or 10 μm) In terms of appearance, it is much slimmer than multimode light.
Multimode fiber: It can carry the transmission of multiple optical signals, that is, multiple optical paths can simultaneously transmit multiple modes of light in a single fiber. Due to the presence of multiple modes of transmission, there is significant inter mode dispersion, poor transmission performance, narrow frequency bands, and small capacity. Therefore, the distance transmitted by multimode fiber is relatively close, usually only a few kilometers, and is commonly used in small capacity, short distance systems. The multimode fiber uses a laser as the light source and uses two wavelengths: 850nm and 1300nm. The center glass core of multimode optical fiber is relatively thick (50 or 62.5 μm) .
In terms of price, under the same specifications, single mode is more expensive than multimode. In practical applications, multimode is basically used in data access optical cables, and the biggest disadvantage of multimode compared to single mode is inter mode dispersion (due to the different rates of the same type of light in different modes). The main use of multimode fiber optic cables in China is 62.5/125, and the difference between the two seems to be due to the different uses after cable formation. The 50% is mostly used for indoor optical cables.
Judging from the appearance color, all single mode optical fibers are yellow. The gigabit multimode is orange red, while the gigabit multimode is light blue.
