What are the application trends of optical fiber cabling?

- Jul 25, 2020-  


According to the classification of transmission modes, there are two types of optical fiber: multi-mode fiber and single-mode fiber. Multimode fiber can transmit several modes, while single-mode fiber can only transmit one mode for a given operating wavelength. At present, the commonly used multimode fibers mainly include 50/125μm and 62.5/125μm. The core diameter of a single-mode fiber is generally 9/125μm.


Multimode fiber—the core is relatively thick (50 or 62.5μm). Because the geometric size of the fiber (mainly the core diameter d1) is much larger than the wavelength of the light wave (about 1 micron), there will be dozens or even hundreds of A mode of transmission. At the same time, because of the large inter-mode dispersion, the transmission frequency is limited, and it will become more serious with the increase of distance. According to the above characteristics, multimode fibers are mostly used in networks with relatively low transmission rates and relatively short transmission distances, such as local area networks. Such networks usually have many nodes, many joints, many bends, and connectors and couplers. The number is large, and there are many active devices used per unit optical fiber length. The use of multimode optical fiber can reduce network costs.


Multimode optical fiber is a kind of multimode optical fiber that is currently used more with the increase in bandwidth requirements of network applications. Because ordinary multimode optical fiber can only support 10G transmission of tens of meters, ISO/IEC 11801 has formulated a new multimode optical fiber. Mode fiber standard grade. This type of fiber is based on 50/125. The two bandwidth modes of the transmission window of the fiber to the LED and laser are optimized. The use of a new type of optical transceiver can enable the OM3 standard fiber system to be In the mode, it supports at least 10 Gigabit transmission to 300 meters.


The core of a single-mode fiber is small (usually about 9μm) and can only transmit light in one mode. Therefore, its inter-mode dispersion is very small, which is suitable for long-distance communication, but there are also material dispersion and waveguide dispersion. In this way, single-mode fibers have higher requirements on the spectral width and stability of the light source, that is, the spectral width should be narrow and stable. Better. Single-mode fibers are mostly used in lines with long transmission distances and relatively high transmission rates, such as long-distance trunk transmission and metropolitan area network construction. The current FTTx and HFC networks are mainly single-mode fibers.


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