中英對照：光纖通信-全文預(yù)覽
【正文】 nuation）與遭受干擾[來源請求]（interference）的情形都改善很多，特別是長距離以及大量傳輸?shù)氖褂脠龊现校饫w的優(yōu)勢更為明顯。對于光纖通信產(chǎn)業(yè)而言，1990年光放大器（optical amplifier）正式進(jìn)入商業(yè)市場的應(yīng)用后，很多超長距離的光纖通信才得以真正實現(xiàn)，例如越洋的海底電纜。但是這些通信方式各有其極限，使用電氣信號傳遞信息雖然快速，但是傳輸距離會因為電氣信號容易衰減而需要大量的中繼器（repeater）；微波（microwave）通信雖然可以使用空氣做介質(zhì)，可是也會受到載波頻率（carrier frequency）的限制。1970年代康寧公司（Corning Glass Works）發(fā)展出高品質(zhì)低衰減的光纖則是解決了第二項問題，此時信號在光纖中傳遞的衰減量第一次低于光纖通信之父高錕所提出的每公里衰減20分貝（20dB/km）關(guān)卡，證明了光纖作為通信介質(zhì)的可能性。這個人類史上第一個光纖通信系統(tǒng)使用波長800納米（nanometer）的砷化鎵激光作為光源，傳輸?shù)乃俾剩╠ata rate）達(dá)到45Mb/s（bits per second），每10公里需要一個中繼器增強(qiáng)信號。同時傳輸?shù)墓β逝c信號衰減的問題也有顯著改善，間隔50公里才需要一個中繼器增強(qiáng)信號。而且中繼器的間隔可達(dá)到100公里遠(yuǎn)。近年來，傳輸速率已經(jīng)進(jìn)一步增加到14Tb/s，每隔160公里才需要一個中繼器。1990年至2000年間，光纖通信產(chǎn)業(yè)受到互聯(lián)網(wǎng)泡沫的影響而大幅成長。fiberoptic municationsOptical fiber is used by many telemunications panies to transmit telephone signals, Internet munication, and cable television to much lower attenuation and interference, optical fiber has large advantages over existing copper wire in longdistance and highdemand , infrastructure development within cities was relatively difficult and timeconsuming, and fiberoptic systems were plex and expensive to install and to these difficulties, fiberoptic munication systems have primarily been installed in longdistance applications, where they can be used to their full transmission capacity, offsetting the increased 2000, the prices for fiberoptic munications have dropped price for rolling out fiber to the home has currently bee more costeffective than that of rolling out a copper based have dropped to $850 per subscriber in the US and lower in countries like The Netherlands, where digging costs are 1990, when opticalamplification systems became mercially available, the telemunications industry has laid a vast network of intercity and transoceanic fiber munication 2002, an intercontinental network of 250,000 km of submarine munications cablewith a capacity of Tb/s was pleted, and although specific network capacities are privileged information, telemunications investment reports indicate that network capacity has increased dramatically since In 1966 Charles and George hockom proposed optical fibers at STC
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