Fiber Optic Historical Development
Since ancient times , it was necessary that man communicate with each other . For such need they actually starting investigation to find a media for exchanging information . Light in a form of smoke, signal fires or even sunlight have been used for this purpose . As a legend , in 1185 BC , Qeen Clytemnestra got informed through a series of 9 signal fires that Troy had fallen and her husband King Agamemnon was passing a distance of 800 Km back to the palace in Argos . By development of Civilization , other shape of light signal or media were used for quick and easy communication which most of them are still found today . Light House for navigation , traffic signal and torches on the top of high mountains are few examples and reminders of this type of communication .
In 1793 , Claude Chappe as a French Doctor and inventor , introduced Optical Telegraph and built a link of 230 Km with 15 stations between Paris and Lille . Though this system rapidly developed in Europe during the first half of nineteenth century but by the invention of Electric Morse Telegraph in 1850 it gradually put out of the service and the modern world of telecommunication began . In 1860 , James Clark Maxwell a Scottish mathematician , physicist and professor of Cambridge University succeeded to present the theory of Electromagnetic Wave Propagation in Waveguides which is now the basic calculation and formula for Optical fibers .
In 1870 , Tyndall an English inventor , succeeded to make a path of light through a bend water jet . This invention opened a new era to the transmission of Optical waves into the light conductors . In 1960 Professor Ali Javan an Iranian scientist succeeded to produce the first Gas Laser .
In 1962 , the first type of Semiconductor Laser introduced and the inventor got the Nobel Prize for that in 1964 . In 1966 , three scientists Charles H. Kao , George A. Hockham and Alain Werts found that Silica Waveguides having total reflection are the best media for the transmission of Optical waves and made the first optical fiber with the loss of 1000 dB/Km . Dr. Kao who got his Nobel Prize for this invention in 2009 , about 43 years later , was in the idea that high loss is due to impurities of glass while others thought that it is the effect of high dispersion of the fiber . As time goes , by development of fiber technology , it proved that the idea of Kao was correct and by removing the impurities from fibers during production the loss will be highly reduced .
In 1970 , Corning glass of United States made the first step Index fiber with the loss of 17 dB/Km at wavelength of 633 nm . Today the commercially made fibers having a loss less than 0.2 dB/Km at wavelength of 1550 nm which is almost close to the theoretical value .
By the application of WDM ( Wavelength Division Multiplexing ) technology having EDFA for Amplification of Optical signals and G.655 NZDS fiber as media , the transmission speed of 45 Mb/s in 1978 exceed 40 Gb/s in these days .
Afshan Cable Co.
Tehran – Iran