专业英语翻译 (13).doc

optic-fiber communication;fiber-optic communicationsoptical fiber communications From the optical communication talent showing itself, has become one of the main pillars of modern communication in the modern telecommunications network, play a decisive role in the. Optical fiber communication as a new technology, its rapid development in recent years, applications broad range of communications in history, but also the important symbol of revolution of world new technology and the future information society information main transfer tool.Optical fiber for optical fiber abbreviation. Optical fiber communication is to light as the carrier of information, with the optical fiber as transmission medium is a means of communication. In principle, constitute the basic elements of optical fiber communication optical fiber, a light source and a light detector. Optical fiber in addition to the manufacturing process, material composition and optical properties for classification, in the application of the optical fiber, used to use for classification, can be divided into communication and optical fiber sensor with optical fiber. Transmission medium optical fiber is divided into general and special two, and functional devices for optical fiber refers to the amplification, shaping, frequency divider, frequency, modulation and optical oscillation features such as optical fiber, and often a function of the device appeared in the form of.The characteristics of optical fiber communication( 1) the communications capacity, transmission distance; a fiber potential bandwidth of up to 20THz. The bandwidth, just one second, then human at all times and in all countries all text data. The 400Gbit / s system has been put into commercial use. The optical loss is extremely low, in light with a wavelength of 1.55 m nearby, quartz fiber loss lower than 0.2dB / km, the ratio of any current transmission medium loss is low. Therefore, transmission distance can reach tens, even hundreds of kilometers. ( 2) small signal interference, good secrecy performance; ( 3) resistant to electromagnetic interference, the transmission quality is good, the electric communication cannot solve all kinds of electromagnetic interference, optical fiber communication is not only affected by all kinds of electromagnetic interference. ( 4) fiber of small size, light weight, convenient installation and transportation; ( 5) and rich material source, good environmental protection, is in favor of saving nonferrous metals copper. ( 6) no radiation, difficult to eavesdropping, because optical fiber transmission light cannot run fiber outside. ( 7) cable strong adaptability, long life. ( 8) a brittle texture, poor mechanical strength. ( 9) fiber cut off and continue to require certain tools, equipment and technology. ( 10) shunt, coupling flexible. ( 11) fiber optic cable bending radius can not be too small ( > 20cm ) ( 12) have the power supply problem. The use of light in optical fiber communication. Because the laser has high directivity, high coherence, high monochromaticity and other significant advantages in optical fiber communication, light is a laser, so they called the laser optical fiber communication.PrincipleOptical fiber communication principle is: the sending end first to transmit information ( such as voice ) into electrical signals, and then the modulation to the laser beam emitted from the laser, causing the light intensity with the electric signal amplitude ( frequency ) changes, and transmitted through optical fiber; at the receiving end, the light signals are received after the detector transform it into an electrical signal, the demodulation after the restoration of the original information.Editor this paragraph developmentOptical fiber communication is the main transmission means in the modern communication network, its development history of only ten or twenty years, has experienced three generations: the short wavelength multimode optical fiber, a multimode fiber and long wavelength of long wavelength single mode fiber. By using optical fiber communication is the communication history great change, beautiful, day, flower, law to wait for 20 many countries have announced no longer construction cable communication line, and committed to the development of optical fiber communication optical fiber communication. China has entered a practical stage. The birth and development of optical fiber communication is an important history of the telecommunications revolution and satellite communications, mobile communications and tied for the nineteen ninties technology. Enter after twenty-first Century, because of the Internet, the rapid development of business and audio, video, data, multimedia application on growth, large capacity (ultra high speed and long distance ) optical transmission systems and networks have more pressing needs. Optical fiber communication is the use of light as a carrier to transmit information, and to optical fiber as transmissi。