Glass fiber optical communications

In January 1992. E. Desurvire (Columbia University Center for Telecommunications Research) reported that optical fibers made from silica glass and traces of erbium can amplify light signals when they are energized by infrared radiation. Desurvire developed an efficient radiation source (referred (o as a laser diode chip) that, when integrated into a fiber optic communication system, can increase transmission capacity by a factor of 10(1. 

The fiber-optics industry has a global presence however, the United States is a major player, dominating the optical cable and fiber markets internationally. According to market-research firm First Research, the U.S. glass and fiber-optic manufacturing industry includes about 2,000 companies with combined annual revenue of 20 billion. The majority of the market is concentrated on companies such as Gorning and PPG Industries, and 80 percent of the market is captured by the fifty largest companies. Japan and the countries of the European Union are also instrumental in the fiber-optic communications industries as both manufacturers and consumers. 

Viable glass fibers for optical communication are made from glass of an extremely high purity as well as a precise refractive index stmcture. The first fibers produced for this purpose in the 1960s attempted to improve on the quahty of traditional optical glasses, which at that time exhibited losses on the order of 1000 dB/km. To achieve optical transmission over sufficient distance to be competitive with existing systems, the optical losses had to be reduced to below 20 dB/km. It was realized that impurities such as transition-metal ion contamination in this glass must be reduced to unprecedented levels (see Fig. 

With the twentieth century came enormous progress in the development of the chemical industry. Chemistry transformed agriculture. Artificial fertilizers provided the means of feeding the enormous, growing population of the world. Chemistry transformed communications and transportation. It provided advanced materials, like silicon for computers and glass for optical fibers it developed more efficient and renewable... 

Optical glass fiber has many desirable characteristics for communication such as ... 

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