Hi I have a question on the transmission coefficient in classical optics. When we say that a medium has a transmittance of e.g. 99%, then 99% of the incident light intensity is transmitted. But will the light also acquire a phase? I tried searching the web, but all I found was this Wiki-article: http://en.wikipedia.org/wiki/Propagation_constant. There it states that the propagation constant has an imaginary term (=phase), but does it also apply to the case I described? Best, Niles.