Refraction of light : Refraction of light E. Alexander Burt
Unit 11 lesson 1
Refraction is bending of light rays : Refraction is bending of light rays Refraction occurs at a boundary
The speed of light must change at the boundary
The angle of the light ray is measured from the normal, as was the case with reflection
If the speed slows across the boundary, the refracted angle will be smaller – the light ray will bend toward the normal.
If the speed increases across the boundary, the light ray will bend away from the normal.
Refraction, illustrated. : Refraction, illustrated.
Refraction may combine with reflection. : Refraction may combine with reflection.
Index of Refraction : Index of Refraction To calculate the exact angle of refraction, we need to know the index of refraction “n”
The index of refraction is the speed of light in a vacuum (c) divided by the speed of light in “stuff” (v)
Index of Refraction, 2 : Index of Refraction, 2 The higher the index of refraction, the more the speed of light changes, and the more the light ray will bend.
Typical indices of refraction are in the range of 1 – 2.5
Snell’s Law : Snell’s Law Snell’s law allows us to calculate the angle of the refracted light ray if we know the angle of the incident light ray and the indices of refraction.