Fibre optics is the science of transmitting light through flexible fibres. The man who coined the word ‘fibre optic is an Indian, Narinder Singh Kapany, something only a few would know about. Kapany was awarded the Padma Vibhushan, and died in USA in December 2020. He was born in the scenic city of Dehradun, graduated from Agra University in 1948 and completed his PhD in 1955 from Imperial College, London. He was the first one to demonstrate the transmission of light through flexible fibre bundles.
He also had over 100 patents registered under his name. His other areas of research were lasers, communications and solar energy. He mentions in his book Sand to Silicon: The Amazing story of Digital Technology, released in 2003: “When I was a high school student at Dehradun, it occurred to me that light need not travel in a straight line, that it could be bent.” Such an important, Noble Prize-worth contribution went unnoticed, unfortunately. A Chinese scientist, Charles K Kao, got the Nobel Prize for physics in 2009 for his research on optical fibre communications.
In his long career, Narinder Kapany wrote many books on fibre optics and business. Fortune named him one of the seven “Unsung Heroes” in 1999 in their ‘Businessmen of the Century’ issue. It was long ago in 1953 when Kapany and his PhD guide Harold Hopkins successfully transmitted high quality images through fibre bundles at the Imperial College. NSK had carefully arranged around 20,000 fibre bundles, each with a diameter of 1/1000 of an inch, which is less than that of a single human hair, and showed light guidance and imaging through a 75-centimetre long fibre.
The results were published next year in Nature journal. “If light is directed into one end of a glass fibre it will emerge at the other end. Bundles of such fibre can be used to transmit images and to transform them in various ways,” he wrote in one of his science papers. He realised the broad potential of this invention in 1955 when he coined the term ‘fibre optics’. The principle behind fibre optics is the concept of total internal reflection in which a light beam, when bent through a glass slab at specific angles, reflects it completely due to difference in densities of different mediums. Fibre optics cable is actually a hair-thin silica glass drawn to lengths. Once inside, light bounces multiple times at the interface going ahead till it reaches the other end.
Today, this technology is used in high speed connectivity, medical care, space science, military and communication technology etc. Kapany’s key contribution was the successful demonstration of a system that used fibre optics for long-distance communication. It is rare to find areas where this stuff is not in use today. The last book that NSK wrote, a memoir called The Man who Bent Light, is expected to be available in the next few months.