What is the smallest, non-zero thickness T of a soap bubble film that appears bl
ID: 2175267 • Letter: W
Question
What is the smallest, non-zero thickness T of a soap bubble film that appears black (indicating destructive interference) when viewed by reflected light with a wavelength lambda of 470 nm in air? The index of refraction of the film is 1.36. There is air on both sides of the film. Assume the index of refraction of air is 1. See diagram below of a section of the film being irradiated by the light. For the same bubble as part, what is the smallest, non-zero thickness T of a soap bubble film that appears BRIGHT (indicating constructive interference)Explanation / Answer
a) 86.4 nm
b) 172.78 nm