How does an Optical Cable work and how do I even know if it's working?

 Function

Optical cables are made up of a thin mirrored glass tube (often called Glass Fibre Cables)

The signal is converted from a digital signal to light and is then reflected down the tube (see below diagram).

Optical cables can temporarily fail or be permanently damaged if tightly bent. A tight bend in the cable will prevent the

light from travelling through the cable.

These cables generally have an effective range of up to 6m (20ft) any longer and the signal will start to degrade. In order

to allow longer cabling a booster or a repeater will be required.

 Checkpoint

To see whether or not a cable is working connect it to the unit that will be sending the signal (i.e. the TV) and point the

opposite end towards a surface. A faint red dot should be visible if all is working.