What is fiber and fiber cabling

The optical fiber is the abbreviation of the optical fibre, which is composed of fine glass wire about 0.1mm in diameter. It is transparent and slender, although it is thinner than hair, it has a guided wave structure which encloses the light and propagates along the axial direction. Optical fiber communication is due to the mysterious structure of optical fibers developed by the optical wave as the carrier, optical fiber for the transmission medium of a communications mode.

At present, the wavelength range of light wave used in optical communication is in the near infrared region, the wavelength is 0.8 to 1.8um. It can be divided into short wavelength segments (0.85um) and long wavelength segments (1.31um and 1.55um). Optical fiber communication technology has been developing rapidly in recent years because of its excellent characteristics. It can be said that this new technology is an important symbol of the world technological revolution, but also the future information Society of the main transmission tools of the network. Generally speaking, the optical fiber communication has the following advantages: Wide transmission band, large capacity of communication, low loss, no electromagnetic interference, thin wire diameter, light weight, rich in resources.

It is precisely because of the above advantages of fiber, that from the 80 's onwards, broadband fiber gradually replaced the narrow band of metal cables. However, the fiber itself has shortcomings, such as the texture is more brittle, low mechanical strength is its Achilles heel. A little attention, will be broken in the outer cable. The construction personnel must have the better cutting, the connection, the shunt and the coupling technology. However, with the continuous development of technology, these problems can be overcome.

In the structured wiring system, the optical fiber not only supports FDDI backbone, 1000BASE-FX backbone, 100base-fx to desktop, ATM backbone and ATM to desktop, but also supports CATV/CCTV and fiber to the desktop (FTTD), so it and copper become the main characters in the structured wiring.

Today, the international popular wiring standard mainly has two, one is North America standard EIA/TIA-568A, one is the international standard Iso/iecis 11801. EIA/TIA-568A and Iso/iecis 11801 recommend the use of 62.5/125um multimode optical cables, 50/125um multimode optical cables and 8.3/125um multimode optical cables.

Single-mode fiber and multimode fiber can be easily judged from the size of the core. The fiber core of single-mode fiber is very small, about 4~10um, only transmits main mode. In this way, the mode dispersion is completely avoided, so that the transmission frequency band is very wide and the transmission capacity is very large. This kind of optical fiber is suitable for large capacity and long-distance optical fiber communication. It is the inevitable trend of future development of optical fiber communication and optical wave technology. (Computer science)

Multimode fiber is divided into multimode mutation fiber and multimode gradient type fiber. The former has larger diameter and more transmission modes, so the bandwidth is narrow, the transmission capacity is small, the refractive index of the latter is reduced with the increase of radius, so the relatively small mode dispersion can be obtained, so the frequency band is wider and the transmission capacity is larger, and the latter is generally used at present.

Several bands of light wave used in optical fiber cabling: 800nm~900nm shortwave bands, 1250nm~1350nm long-wave bands and 1500nm~1600nm Long-wave wavelengths.

In these bands, the performance of optical fiber transmission is the best, especially in the central wavelength of the band. Therefore, multimode fiber operating wavelength of 850nm or 1300nm, while the operating wavelength of single-mode fiber is 1310nm or 1550nm.

The two major international standards for optical fiber cabling attenuation characteristics of the following provisions:

As can be seen from the above chart, the two regulations are very different, are very strict. As a result, the longest distance of the fiber as the backbone wiring has also been stipulated. Fiber optic cable used in the trunk, each floor wiring between at least 6 core cable, advanced applications preferably can use 12-core cable. This is from the application, backup and expansion of three aspects to consider. As for the optical fiber networking mode is also very flexible. Can be achieved: (1) point-to-point. A high-speed channel is established between the two computers. The transfer rate is several Mbps to hundreds of Mbps, up to 2 km (multimode) to 5 km (single-mode). (2) Star-type network. Based on the optical fiber network equipment, the star-type network topology is established. (3) Ring network. The signal regenerator is connected by the optical fiber to form a loop.

With the development of science and technology, the higher and newer requirements of optical fiber are put forward. The old wiring standards have been tested in practice and are now being revised. In addition to revising the original specifications, some new requirements will be added. Believe that fiber optics will play a more important role in it. It is not difficult to anticipate the bright future of optical fiber communication and fiber cabling.