A layer of transparent plastic (n = 1.59) on glass (n = 1.52) looks dark when viewed in reflected light whose wavelength is 570 nm in vacuum. Find the two smallest possible nonzero values for the thickness of the layer.
answer in nanometers
We assume that light strikes at near normal incidence.
For the transparent plastic to appear dark there is destructive interference
Ray 1: ...
The solution calculates thickness of a layer of transparent plastic using interference of light