IB Communication topic - F3 Optical fibres

1. Refraction
Snell’s Law
.........but as the angle of incidence increases, eventually:

2. ...you reach the critical angle:
This is the same as saying the angle of refraction is 90°
....but

3. Refractive Index is the ratio of wave speeds in two mediums:
So:
From before:

4. When light hits a surface at an angle of incidence bigger than the critical angle then:
TOTAL INTERNAL REFLECTION
None of the light is transmitted ALL the light is reflected
This is the basis of Optical Fibres

7. Dispersion
This is when signals spread out as they travel along
the fibre.
This can cause problems with data

12. 1.
2.