Refractive index
Physics: IB Diploma Higher Level, topic 3.4.4
Snell's Law
Snell's law relates indices of refraction to the angles of incidence and refraction.
Equation
- Snell's law is:
- The ray of light begins in the medium with index of refraction n1.
- θ1 is the angle of incidence.
- n2 is the index of refration of the medium the light passes into.
- θ2 is the angle of refraction.
Direction of bending
- When light travels from a less optically dense medium to a more optically dense medium, it bends towards the normal.
- When light travels from a more optically dense medium to a less optically dense medium, it bends away from the normal.
- The more optically dense a medium is, the slower light travels through it, and therefore the larger its index of refraction.
Test yourself on Refractive index
Light travels at 3 x 108 m/s. If light passes through a material at 1.5 x 108 m/s, what is the material's index of refraction?
Assuming that the speed of light in air is the same as the speed of light in a vacuum, what is the index of refraction of air?
If a medium has a high index of refraction, what will happen to a beam of light entering from air?
What is the correct equation for Snell's law?
Fill in the blank: index of refraction = 1 / ___(critical angle)