Snell's law

If we have two objects with ‘absolute’ refractive indexes of and , we can say that:

Where:

• is the refractive index of the first material.
• is the refractive index of the second material.
• is the angle at which light enters the boundary
• is the angle at which light leaves the boundary

Assuming we know 3 out of the 4 unknowns, we can find any of them. We can re-arrange the formula above into any of:

This is Snell’s law!

What is each material?

• The first material is the material the light starts in.
• The second material is the material the light goes into.