Refractive index of different colors

[MrEinstein]

Homework Statement

I have to design an experiment to determine the difference in refractive indices for different colors.

Assume you have : color filters,glass block

Homework Equations

The Attempt at a Solution

I want to do it buy shining a white laser light through filters into the glass block and measuring the angle of incidence and refraction using a protractor. But they say to take into account the fact that the variation of refractive index with frequency is very small. So what else can I do to take that into account?

 

[mfb]

Total reflection might be interesting to study, as it is quite sensitive to small angle differences.
A prism would be easier, of course.

 

[MrEinstein]

But what exactly do we use to measure the angle of refraction? It's going to be such a small angle difference that a protractor can't help. Yeah,with a prism it would be easy but they say that you have a rectangular glass block so they clearly want you to use it.

 

[mfb]

Measure the position of the beam at different points and use trigonometry? If you just need the difference and not an absolute value, it is easier.

 

[MrEinstein]

Ahhh trigs. Length can be measured more accurately than angles. This explains the glass block, instant right angled triangle.
Thank you man