Thanks. I think you got it right. Beacause this also could be found on the text I'm reading
"It was found that resonance effects become important when the size of the inhomogeneity has the order of magnitude of the wavelength."
What does the below senetence mean? I don't understand it, maybe because of my not so good english.
"When the wavelength becomes of the same order as the layer thickness, resonance occurs. "
Does it mean when the wavelenght and layer-thickness are exactly equal (e.g. both 0.1m)? Thanks.