Index refraction

[bahaar]

Hi.
In the textsbook i raed for frequencies that (real part of index refraction) |n|~1>>|K| (exitinction coefficient), we have transparent matter (weak absorbtion). If we have a bulk matter with big diameter, that there are no transmitted light ( i don't know it is possible or not), our matter be transparent or it is meaningless.

Thanks.

 

[DrDu]

Yes, that's kinda convention. Take water for example. In some hundred meters depth, the ocean is completely dark as all light from the sun has been absorbed, although we would usually consider water to be transparent.

 

[chrisbaird]

That's the nature of approximations; they only work in certain regions of parameter space. For example, mostly transparent materials can only be treated as perfectly transparent if the object of interest is thin (how thin depends on how accurate you want the approximation to be).

 

[bahaar]

Thanks.