- Tyndall and Graham Bell are some of the scientists who laid the theoretical foundations for what would later become fibre optics in the 19th century.
- Who invented fibre optics? Narinder Singh Kapany is known as the ‘father of fibre optics’, although Charles Kuen Kao is considered the ‘father of fibre optic communications’.
In the collective imagination, fibre may seem like a relatively recent technology. However, the first fibre optic telephone connection was made in 1977, although the technology itself was born two decades earlier.
Let’s first define what fibre optics are before looking at their origins and historical evolution.
Fibre optics: what is it?
Fibre optics can be briefly summarised as the transmission of data through thin glass or plastic threads that send information via pulses of light, a technology that is essential for telecommunications and the Internet today.
Thanks to the refraction and reflection of light, this technology transmits data through optical cables.
Thanks to the ability of light rays to remain undistorted, retain their power and travel long distances, information transmission is fast and stable.
It is precisely this ability to transmit light that forms the theoretical basis for the creation of fibre optics in the 1950s, something that had already been studied in the 19th century.
John Tyndall: experiments in light transmission
In the 1870s, Irishman John Tyndall (1820-1893) demonstrated that light had the ability to travel within a material through internal reflection, which, as mentioned above, is the theoretical basis for the subsequent development of fibre optics.
This physicist’s studies led, among other things, to what is known as the Tyndall effect: a physical phenomenon that everyone has seen, even if they are not aware of the science behind it, such as dust particles suspended in a beam of light or the blue colour of the sky.
Graham Bell’s photophone
The Scotsman Alexander Graham Bell (1847-1922) is an old acquaintance of this blog due to a controversy that lasted for decades, even after the two protagonists of the story had died; a dispute that was settled in 2002 by the United States Congress, which recognised Antonio Meucci as the inventor of the telephone.
But returning to fibre optics, in 1880 Graham Bell, together with the American Charles Sumner Tainter (1854-1940), developed a device known as the photophone.
This device allowed sound to be transmitted through light, also laying the foundations for the subsequent development of fibre optics, although the truth is that the photophone was never implemented due to technical limitations.
This experiment consisted of focusing sunlight with a mirror and then speaking into a mechanism that caused it to vibrate, while at the receiving end a detector picked up the vibrating light and decoded it into voice in the same way that the telephone did with electrical signals.
Although the photophone was not developed as its inventors would have liked, it did demonstrate the feasibility of voice transmission using light.
The father of fibre optics: Narinder Singh Kapany
Although experiments using glass and fibres for light transmission were carried out in the late 19th and early 20th centuries, the truth is that efficient transmissions were not achieved.
This changed with the Indian physicist based in the United States, Narinder Singh Kapany (1926-2020), who would go down in history as the father of fibre optics.
In an article published in 1954 in the journal Nature, he explained how he had managed to send a beam of light through 75-centimetre-long glass cables with virtually no loss in the transmission signal.
His 1967 work, Fibre Optics: Principles and Applications, addressed, as its name suggests, both the theoretical foundations and the possible practical applications of the then emerging technology of fibre optics.
The father of fibre optic communications: Charles Kuen Kao
Chinese scientist Charles Kuen Kao (1933-2018) received the Nobel Prize in Physics in 2009 ‘for his revolutionary achievements in the transmission of light in fibres for optical communications’, according to the organisation responsible for awarding the prestigious prizes.
The Swedish Academy also explained that Kuen Kao was deserving of the distinction because he ‘initiated the search for and development of low-loss optical fibres used today in fibre-optic communication systems’.
For all these reasons, this Asian scientist is considered the father of fibre optic communications.
Kapany vs Kao controversy
The ‘paternity’ of these two scientific authors on fibre optics is what lies behind the controversy surrounding the awarding of the Nobel Prize to Kao, since, even though the Chinese scientist was the one who adapted the use of fibre to telecommunications, without the previous contributions of the Indian scientist, it would have been impossible.
