Optical fibre communication: A revolution in communication engineering 

    Optical fibre Design: A breakthrough in communication engineering 

                 Nowadays, in every walk of human life the usage of optical fibre is an indispensable one. Because of immense band width, very low transmission loss, small size, light weight and electrical isolation optical fibre encompasses the usage in diverse fields. Optical fibre communication used in the medical field for diagnosis and surgeries, data storage, transmission and reception of optical signals in telecommunication and networking for servers with speed and accuracy. Among its plenty of applications, long distance communication occupies a dominant space.  

History of long-distance communication 

                         The very foundation for the long-distance communication is laid by, Johannes Kepler, a German mathematician and astronomer in the year 1611 and subsequently a Willebrord Snell derived his famous formula for the refraction of light. Without the contribution of these two legendary scientists it is not possible to have this fantastic connectivity today. In the year 1840s it was proved that light could be guided along jets of water. The scientists took advantage of the phenomenon called total internal reflection. Because water has a higher refractive index (a measure of the ability to bend light waves) than that of air, light beams will remain inside the water. 

Even before many centuries ago a long-distance communication was prevailing in this society. For instance, smoke signals and flag signals to sailing ships were common on those days. Semaphore tower developed in France in the year 1790 is the first mechanical optical communication system. Signal block occurred while light travel through air, cloud and Hill. After the invention of telephone and telegraphy many of the old mechanical systems become obsolete. Instead of light an electrical signal was used by Alexander Graham Bell in the telephone. The earliest real showcase of image transmission through glass was done by the German medical student Heinrich Lamm in 1930. He was intelligent to transmit the image through a light bulb filament, but the quality was extremely poor. In order to achieve communication systems further 20 years were consumed. The first transmissions of images through bundles of tiny elicited glass fibres were made independently in 1954 by Abraham van Heel, and the team of Harold Hopkins and Narinder Kapany. This was the discovery that paved the way for the birth of the field of fibre optics. 

The major problem with the initial fibre optic systems was signal intensity. Signals transmitted through glass tend to attenuate, or perish, leaving the receiver on the end with a nebulous, puzzling signal. This was because the glass fibres had a structural inhomogeneities due to the presence of impurities. Ordinary light sources were not so powerful or easily controllable. But the laser provided a focused, powerful signal and materials with higher quality, pure, coated glass fibres reduced the attenuation. The laser invented in 1960 was the principal step forward in providing a powerful, accurate light source. It provided a focused, coherent beam of light with an exact wavelength. Now scientists were able to tune a light wave transmission just as precisely as a radio transmission. 

  In 1970, Robert Maurer, Donald Keck, and Peter Schultz developed a way of formulating fused silica. Not long after the Corning scientists noticed another way of improving the flexibility of the fibres by doping them with germania (germanium oxide). The first practical fibre optic communication system was put into place in September 1975 in Dorset, England. AT&T tested its first fibre optic system in Chicago in 1976. They linked three office buildings in the downtown core with 2.6 kilometres (1.6 miles) of optic cable. They began tests on April 1, but were beaten to the blow by GTE, which was able to get 10 kilometres (6.2 miles) of fibre optic cable up and running for public use in Long Beach, California, on April 22. GTE’s lines couldn’t carry as much information as AT&T’s, but it was the first working American system. After these initial successes, the first large network to be installed was the Boston-New York-Washington corridor. MCI Communications Corp. had started putting in an improved system using distinct technology standards in 1982 with faster data transfer, more bandwidth, and fewer repeating stations. (Repeating stations amplify waning signals for transfer along the next section of cable.) Customizing and shaping optical fibres to nanoscale proportions is rapidly becoming a focus area of research and is important for the ultimate success of future in-fibre optical systems and novel technologies.  

Post Views: 58