Envisaged in the article Charles Kao of the United States in 1970 Corning Glass Company, with improved chemical deposition (MCVD method) created the world's first ultra low-loss fiber, an optical trigger for explosive racing to develop. Although Corning Glass company produced only several meters long, attenuation is about 20dB/km, and a few hours later damaged. But it proved the technology and processing method of manufacturing communications using ultra low-loss fiber is entirely possible, that is found to achieve low loss transmission ideal for optical transmission media, is a major breakthrough in optical communications research.
Since 1970, the developed countries of the world the study of optical fiber communication devoted a lot of manpower and resources, it comes hard, scale and speed faster than people expected, so that the optical fiber communication technology has made extremely remarkable progress.
From the perspective of attenuation of the optical fiber:
O seven years: 20dB/km
O nine years: 0.14dB/km
It was close to theoretical loss limits for silica fiber 0.1dB/km.
From the perspective of optical devices:
197 o, Bell Labs developed the world's first continuous wave at room temperature of aluminium gallium arsenide semiconductor lasers, found a suitable light source for optical fiber communication devices. Later evolved into better performance, long life up to bar tens of thousands of hours of the heterojunction lasers and now single-longitudinal-mode laser with distributed feedback (DFB) as well as multiple quantum well lasers (MQW). Light receiving device from simple Silicon PIN diode to the quantum efficiency of 90% ⅲ-ⅴ avalanche photodiode APD.