- #1
revacious
- 11
- 0
Interference with thin film :(
A soap film in air is 320nm. thick. If it is illuminated with white light at normal incidence, what colour will it appear to be in reflected light (assume that the index of the soap film is 1.33).
The condition for destructive interference is given by:
2tnf = (m + ½ )λ
The condition for constructive interference is given by:
2tnf = mλ
Well... the light is going from air (n=1) to film (nf=1.33) so there will be a phase change of Pi/2? Not really sure how to start to be honest.
Sorry for amateur question!
Homework Statement
A soap film in air is 320nm. thick. If it is illuminated with white light at normal incidence, what colour will it appear to be in reflected light (assume that the index of the soap film is 1.33).
Homework Equations
The condition for destructive interference is given by:
2tnf = (m + ½ )λ
The condition for constructive interference is given by:
2tnf = mλ
The Attempt at a Solution
Well... the light is going from air (n=1) to film (nf=1.33) so there will be a phase change of Pi/2? Not really sure how to start to be honest.
Sorry for amateur question!