From the late 1980s, fiber-optic communications gradually shifted from short-wavelength to long-wavelength, from multimode fiber to single-mode fiber. At present, single-mode fiber is widely used in the national cable trunk network and the provincial trunk line network. Multimode fiber is only limited to some LANs with low speed.Currently,the fiber that people talk about refers to single-mode fiber. Single-mode fiber has the advantages of low loss, large bandwidth, easy upgrade and expansion, and low cost, and is widely used.
As people’s living needs improve further, the Internet becomes an important part of life.In order to comply with the development of the information age, integrated wiring technology and products are constantly being updated, especially the large-scale research and development of fiber optic cables. There are many different types of fiber optic cables of different types and uses in the market. How to choose a practical type in the face of many optical fibers? How to choose the best quality fiber optic products?
Main categories of optical fiber
According to the transmission mode classification, the optical fiber has two types of multimode 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. The commonly used multimode fibers are mainly 50/125m and 62.5/125m. The core diameter of a single mode fiber is typically 9/125 m.Multimode fiber—the core is thicker (50 or 62.5m). Since the geometry of the fiber (mainly the core diameter d1) is much larger than the wavelength of the light (about 1 micron), there are dozens or even hundreds of fibers. Propagation mode.At the same time, because of the large dispersion between modes, the transmission frequency is limited, and the increase with distance is more serious.According to the above characteristics, multimode optical 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 of components, the number of active devices used per unit fiber length, etc., the use of multimode fiber can reduce network costs.
The single-mode fiber has a small core (generally about 9 m) and can only transmit one mode of light.Therefore, the dispersion between modes is very small, suitable for remote communication, but there are still material dispersion and waveguide dispersion, so single-mode fiber has higher requirements for the spectral width and stability of the light source, that is, the spectral width should be narrow, and the stability should be good.Single-mode fiber is mostly used in lines with long transmission distance and relatively high transmission rate, such as long-distance trunk transmission, metropolitan area network construction, etc. The current FTTx and HFC networks are mainly single-mode fibers.
The difference between single mode fiber transceivers and multimode fiber transceivers
A fiber optic transceiver is an Ethernet transmission medium conversion device that exchanges electrical and optical signals of an Ethernet, and optical fibers that transmit data over a network are classified into multimode fibers and single mode fibers.From the networking application, because multimode fiber cannot be transmitted over long distances, it can only be used for networking inside buildings and between buildings. However, because multimode fiber and corresponding fiber transceiver are relatively cheap, it is still within a certain range.Got the application. Many schools also use multimode fiber when they build an internal campus network.
With the advancement of technology, single-mode fiber began to enter long-distance networking operations (from a few kilometers to more than one hundred kilometers), and the development momentum is very rapid, in a few years, from high-end applications into the homes of ordinary people, For example, many homes now use optical transceivers (so-called FTTH mode, fiber-to-the-home) when they open the network. The use of optical transceivers has become a very common form of value-added services for broadcasting and television.
Using fiber optic transceivers for networking, the advantages are not only stable, but what else? That is speed! 100M full duplex, even higher speed than 100 full duplex: 1000M full duplex.
It extends the network transmission distance limit from 100M to more than 100KM for twisted pair, which can easily realize the interconnection between the motherboard server, repeater, hub, terminal and terminal. When choosing fiber-optic networking, we will strengthen the understanding of optical fiber, popularize relevant knowledge, and select the best-performing fiber through comprehensive consideration.