AQA AS Physics Chapter 5 Optics LATEST UPDATE

AQA AS Physics Chapter 5 Optics LATEST
UPDATE

Normal
Imaginary line perpendicular to the boundary between two materials or a surface.
Partial reflection
When some of the wave bounces off a surface, as it does when light moves from air to
a refractive substance.
Refractive index
Ratio of sin i to sin r. Also the ratio of the speed of light in a vacuum to the speed of light
in the material. Also the ratio of the wavelength of light in a vacuum to the wavelength of
light in the material.
1/n
What to replace n with when calculating angles and the light is exiting the material into
air, not the other way round.
Critical angle
Angle of incidence that gives an angle of refraction of 90 degrees.
Total internal reflection
Caused when the angle of incidence exceeds the critical angle. Only happens when
attempting to move into a material with a lower refractive index.
Optical fibre
Thin flexible transparent fibre.
Endoscope
Device using optical fibres used for seeing inside the body.
Modal dispersion
Effect where light takes different routes of different lengths and spreads out the signal.
Another way of saying multipath dispersion.
Spectral dispersion