# How to calculate the Refractive index of a glass sheet

My question is how to find the $n$ of a glass sheet with just aiming a laser beam to that.

I've got lot of ways that let me find the $n$ ( Refractive index ) but I need the whole part of the Refractive index that includes $n$ (Refractive index), $k$ (Extinction coefficient) and $α$ (absorption coefficient). ( because I want to calculate the amount of absorption of the glass sheet )

How can I find the all ( $n , k , α$ )? Can I find it by using the thickness of my glass sheet?

Notice that I want to find a way that uses a laser pointer

• Please set out the "rules". Obviously you can measure the absorption coefficient by seeing how much absorption there is (on top of the reflection losses) as the light traverses the glass. How are $k$ and $\alpha$ different? – Rob Jeffries Aug 22 '15 at 17:54
• sir, what do you mean? I didn't understand how should I calculate the $n$ and $k$ – David 2000 Aug 22 '15 at 19:55
• What do you mean by "find" or "calculate"? You cannot derive the absorption from the (real part of the) refractive index. As you have already been told in another question. – Rob Jeffries Aug 22 '15 at 20:44
• You may be running into some resistance here for several reasons: (a) you seem to be just asking for a formula without understanding the physics and without caring about understanding the physics; (b) the is closely related to a question you asked only a few hours before and you don't seem to have fully accepted the answers you got; (c) your wording is ambiguous: do you want a theory and table based answer or an experimental answer; and (d) You seem to answer comment requesting clarification by simply repeating the original question and not offering any clarification. – dmckee Aug 22 '15 at 23:29
• For a : how do you say I don't care about understanding physics? why? For b : but I've fully accepted those answers and that's why I asked this question. when I saw their answers, I searched about that and learned many things for c : a combination of those two is the best for d : sorry about that! – David 2000 Aug 23 '15 at 4:40