A hair-thin thread of glass can carry a phone call, a film, or a surgeon view of your insides, all as pulses of light bouncing thousands of times along its length without ever leaking out.
An optical fibre guides light along its length by repeated total internal reflection. The light strikes the walls at angles greater than the critical angle, so none escapes. Fibres are used for high-speed communications, where they carry huge amounts of data with little loss, and in medical endoscopes.
An optical fibre is a thin glass fibre that carries light along its length by repeated total internal reflection.
The light reflects many times along the fibre and can even follow gentle bends.
Send a ray into the fibre and watch it bounce along by total internal reflection, even around a bend.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
Optical fibres carry light along their length by...
For light to stay inside a fibre, it must hit the walls at an angle...
One important use of optical fibres is...
A medical instrument that uses optical fibres to look inside the body is...
The physics is total internal reflection; the applications follow from carrying light with little loss.
Light stays in a fibre because of total internal reflection, not because of any mirror coating. If a ray meets the wall at less than the critical angle it refracts out and the signal is lost, so the fibre must keep every reflection above the critical angle.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
Light stays inside an optical fibre because at each wall it undergoes...
An advantage of optical fibres for communication is that they...
If light meets the wall of a fibre at less than the critical angle, it will...
Optical fibres mastered. Lenses are next in the light strand.