TABLE OF CONTENTS John Tyndall, a British physicist, demonstrated to the Royal Society in 1870 that light can be guided along a curved stream of water. Owing to total internal reflections light gets confined to the water stream and the stream appears luminous. A luminous water stream was the precursor of an optical fiber.
Electronic communications use radiowaves and microwaves to carry information over copper wire and coaxial cables. The information carrying capacity of these wires is highly restricted in view of their limited bandwidths and does not suffice for modern needs. The use of light waves, in place of radiowaves and microwaves, enhances tremendously the number of signals that can be transmitted simultaneously. Historically, the first technical effort to use light waves as a vehicle of communication was due to Alexander Graham Bell. He invented the photophone in 1880 which transmitted speech on a beam of light. By 1960, it had been established that light could be guided by a glass fiber but the fibers available at that time heavily attenuated light propagating through them. It was the fabrication of low-loss glass fibers by Corning Glass Works and the invention of continuous wave room temperature solid state diode lasers in 1970 that made optical communications practicable. The overwhelming advantages of optical fibers over the traditional wires and coaxial cables were soon recognized. Commercial communication systems based on optical fiber cables made their appearance by 1977. The area of photonics has been ushered in.
Apart from the use as a communication...
