The core principle of modern optical communications using
guided light can be traced back to the 19th century when Daniel
Colladan, a Swiss Physicist demonstrated this effect in 1841. By the
mid-20th century copper wires were well established as a wave-
guide for telecommunication purposes. However, using copper
wires to transmit signals proved to be rather expensive and the
performance of the signal was limited by the amount of fre-
quencies that could be used. Therefore, alternative waveguides
were researched upon aiming to reduce the weight and cost of
implementation and to increase the operational bandwidth. This
limitation was overcome with the invention of the LASER in the
1950s, followed by the introduction of the optical fibre waveguide
by Kao and Hockam as an alternative to copper wires. Kao re-
volutionized the telecommunications industry by suggesting that
loss could be reduced to less than 20 dB/km using optical fibre and
Keck et al. [1] achieved the attenuation figure of 20 dB/km in 1970.
With the advancement of research activities driven by the need for
faster and broader transmission capacity, this technology which is
based on a waveguide made of glass soon became the backbone of
modern communications systems.