What is Fibre?

A single optical fibre is a long strand of glass that are stretched until they are about the thickness of a human hair. Charles Kao and Charles Hockham demonstrated in 1966 that these strands of glass can carry information by transmitting light through them. These strands are incorporated into cables to protect them from the elements.

At the time, 99% of light per kilometre was lost, but since 1970 when the Corning Corporation developed a glass fibre that offered much lower light loss, glass is so pure that 60% of light transmitted is received 10km, which is almost like being able to look through a window 10km thick. For greater distances, amplifiers are used to boost the light signal.

Lasers diodes and LEDs (light-emitting diodes) are both commonly used as sources of light that are flashed and then received by electronics at its destination like Morse code. Laser diodes however, have taken the lead in high speed data applications.

Although fibre is much faster than other mediums like copper, it doesn’t travel at the speed of light but on average 31% slower. This is primarily due to the glass slowing the light down but also due to our planet’s atmosphere, which in both cases, is known as refraction in physics.

How is Fibre Different to Copper or Wireless?

Both copper and wireless technologies suffer from interference. Copper cables can interfere with one another and wireless technologies can face interference from mobile phones, microwaves and other radio sources. Both are also limited to short distances of up to a few miles in rural areas.

Fibre doesn’t suffer from this interference, so it quite happily be laid down alongside power cables or gas lines. It also doesn’t emit radiation nor conduct electricity, making it an ideal fit for highly flammable and other sensitive environments.

What is interesting however, is that mobile networks are usually connected to one another through fibre and it’s the cell towers that provide wireless connectivity between a mobile phone and the fibre network.