Development and Prospect of Optical Fiber

Abstract of the historical development of optical fiber communication technology and features, and the development trend of optical communication technology were discussed.

Keywords: characteristics of optical fiber communication technology

a future, optical fiber communication optical fiber communication
history of the birth and development is an important revolution in telecommunications history. In 1966, the Chinese-American Kao (CKKao) and Hawke Hamm (CAHockham) published a paper that predicted a low-loss optical fiber for telecommunications, knocking on the door of the optical fiber communication, attracted attention. In 1970, Corning developed the first time 20dB/km loss optical fiber, optical fiber communications era began. 1977 United States 7000 meters apart in the Chicago telephone exchange between the two, the first multi-mode optical fiber with the successful conduct of the optical fiber communication. 8.5 micron wave band as the first generation of multi-mode optical fiber communication systems. In 1981 they achieved between the two telephone office use 1.3 micron multimode fiber communication system, for the second generation optical fiber communication systems. 1984, achieved a 1.3-micron single-mode optical fiber communication system, the third generation optical fiber communication systems. Also in the late 80's 1.55-micron single-mode fiber to achieve a communication system, that is the fourth generation of optical fiber communication systems. Light wavelength division multiplexing to improve speed, increase transmission distance with light amplification system, for the fifth-generation optical fiber communication systems. The new system, coherent optical fiber communication systems, has reached the level of field experiments will be applied. Optical soliton communication systems can be extremely high rate of late 20th century or early 21st century likely to be practical.

Second, the characteristics of optical fiber technology
(1) a very wide band, communications capacity. Copper or fiber optic cables are much larger than the transmission bandwidth, fiber optic communication systems in the light of the modulation, modulation and fiber dispersion characteristics. For single-wavelength optical fiber communication systems, due to the electronic bottleneck terminal equipment can not play fiber bandwidth advantage. Usually a variety of complex techniques to increase transmission capacity, especially now that the dense wavelength division multiplexing technology greatly increased the transmission capacity of optical fiber. Currently, the single-wavelength optical fiber communication systems in general 2.5Gbps transfer rate to 10Gbps.

(2) low loss, long-distance relay. Currently, the product of quartz fiber loss can be less than 0 ~ 20dB/km, this transmission loss than any other transmission medium losses are low; if the future use of non-quartz system, very low-loss optical fiber, the theoretical analysis of the lower loss can be reduced. This means that through the optical fiber communication systems can span greater distances without repeaters; for a long-distance transmission line, due to reduction in the number of relay stations, system cost and complexity can be greatly reduced.

(3) anti-electromagnetic interference capability. Fiber raw material is an insulator made of quartz material, not easily corrode, and insulation. Associated with it an important feature of the optical waveguide for electromagnetic interference immunity, it is not the nature of the lightning interference, ionosphere interference changes and sunspot activity, are not subject to anthropogenic emissions of electromagnetic interference, it can also be used high voltage transmission line parallel to the erection or combined to form composite conductor with the power cable. This is for the strong electrical fields (such as power transmission lines and electrified railway) communications systems in particular. With the ability to remove the electromagnetic pulse effect, optical fiber transmission system is also particularly suitable for military applications.

(4) no crosstalk interference, security and good. In the process of radio transmission and electromagnetic wave leakage will cause the transmission channel crosstalk, and easy listening, poor security. Light in optical fiber transmission, because the optical signal is perfectly confined waveguide structure, and any leakage of radiation around the fiber are absorbed by the opacity of the foreskin, even in the corner, the light leakage is very weak, even if the fiber optic cable Total lot, adjacent channel crosstalk interference will not occur, while in the cable outside, tapping into the fiber can not transmit information.

In addition to these features, there are small fiber diameter, light weight, soft and easy to lay; fiber rich raw material resources, low cost; temperature stability, long life. As more optical fiber communication has unique advantages, which can be applied not only to the trunk lines of communication can also be used in electric power communication control system, for industrial monitoring, control and use in the military field but also more and more widely.

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