aka...science room
fiber optics
Is it a plant? Is it a light bulb? No! It’s a fibre optic cactus.
Bundles of optical fibres carry light from the central light source (a bulb) along their length. The light appears as a bright point of coloured light at the end of the fibres but no light escapes along their length.
Optical fibres are strands of incredibly pure glass, about the same thickness as a human hair.
Fibre optic technology has revolutionised the telecommunications industry. It's thanks to optical fibres that we have cheap, fast transatlantic phone calls, internet access and cable TV.
Fibre optics are used in medicine too – a fibre optic endoscope can be placed inside your digestive tract to have a look at what’s going on.
So why doesn’t the light leak out along the length of the fibres? The answer lies with total internal reflection.
When light travels from a dense medium to a less dense one, some light is always reflected at the boundary. However, when the angle of incidence is greater than a specified critical angle, all of the light is reflected.
<< Go Back