Effect on visibility of thin films due to interference

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
Sign up Log in
35 replies · 5K views
brochesspro said:
Sorry, I didn't get you.
Suppose on hitting the film from the left only 5% is reflected. The other 95% reaches the far side of the film, where 75% is reflected. (Is this possible? I don't know.) So then 75% of that is reflected from the LHS, the other 25% emerging. The reflected portion returns to the RHS, 75% of that being reflected and 25% emerging as the third ray directed leftwards.
We have, in the first three rays going leftwards from the film:
5% in the first
95%*75%*25%=15.7% in the second
95%*75%*75%*75%25%=9% in the third
 
Physics news on Phys.org
haruspex said:
Suppose on hitting the film from the left only 5% is reflected. The other 95% reaches the far side of the film, where 75% is reflected. (Is this possible? I don't know.) So then 75% of that is reflected from the LHS, the other 25% emerging. The reflected portion returns to the RHS, 75% of that being reflected and 25% emerging as the third ray directed leftwards.
We have, in the first three rays going leftwards from the film:
5% in the first
95%*75%*25%=15.7% in the second
95%*75%*75%*75%25%=9% in the third
So this supports my assumption, right?
 
brochesspro said:
So this supports my assumption, right?
That was an explanation of how the third ray to the left could be more significant than the first one, so an analysis that only considers the first two is incomplete.
 
haruspex said:
That was an explanation of how the third ray to the left could be more significant than the first one, so an analysis that only considers the first two is incomplete.
So in short, no, right?
If so, I think I will stop thinking about this problem.