Sir Charles Kuen Kao 高錕博士 – The Father of Fibre Optics , broadband

  Who was Sir Charles Kuen Kao 高錕博士 GBM KBE FRS FREng, ph.D ? For those who enjoy much of the internet / broadband communications, they should thank him for his ground breaking achievements in pioneering the development and employment of optical fibres (glass fibres) in telecommunications. Using light to transmit data is much faster than in copper wires. Optical fibre has been used in the backbone of the internet (trunk lines) for years but you will see many ISPs are using optical fibres for access networks also (between the customers and ISPs), PON (passive optical network): fiber-to-the-curb, fiber-to-the-home , fiber-to-the-building , etc.

  Actually , there are two fathers of Fibre Optics ,  One is Professor Kao and the other is Narinder Singh Kapany (an India-born American physicist) but it was Professor kao who really made the employment of optical fibres in telecommunication a reality.

  There are many advantages using optical fibre over copper wires :
-much faster transmission rate, light travels much faster than eletrons in metal wires
-light weight
-smaller diameter , thus pack more fibres for a given diameter than copper wires, transmit more data (much higher carrying capacity).
- cheaper
- less signal degradation (electrical signals in copper wires experience impedance and it is frequency-dependent)
- no electromagnetic interference and light signal in one fibre does not interfere with light signals in other fibres in the same fibre bundle.
- longer life span than copper wires.

 Like many other things , there are also disadvantages:

- fragile (glass breaks, you can not bend optical fibre too much)
- often requires repeaters and optical amplifiers to boost light signals over long distance.

  There are a few types of optical fibres
- singe mode (for long distance , but only for one wavelength of light)
- multi mode (for shorter distance and multiple wavelengths of light)

   multi mode is further divided into stepped index and graded index multimodes .

 Whether it is single mode or multi mode optical fibres, light relies on refractive indices of materials and total internal reflection  to travel along the fibre.

   Another type of optical fibre is called Microstructured Optical Fibre which relies on the structure of the light wave guide to manipulate the light travel rather than total internal reflection. Three types of Microstructured fibres : Phtonic Crystals , Air-clad or double clad fibres and Fresnel fibres.

  Without getting too much into technical details and bore my readers, let's return to Dr. Kao.   Dr. Kao was born in Shanghai, China in 1933 and moved to then British Hong Kong in 1948. He obtained his doctorate in electrical engineering in 1965 from University of London under the supervision of Professor Harold Barlow. Since then , he was awarded many honorary doctorate degrees from various universities all over the world (Taiwan, Hong Kong , Australia , Britain , United States ). In 2009, he was awarded the Nobel Prize in Physics for his works in optical communication.

  Unfortunately, Dr. Kao suffered from Alzheimer's disease in his later years (2002 - ) and passed away on 23 rd September, 2018 at the age of 84.

  Many just remember the names of stars , entertainers , singers or politicians but not many would know the names of those who worked behind the scene of many technologies we took for granted. Professor Kao was one of them and I hope you will think of him every time you use the internet (although optical fibres are used in many areas including medicine). We should respect those who contribute to the world, a real ph.D in my opinion.


















Professor Kao and his wife.