Hello!
I need to conduct an experiment, where I should measure thicknesses of different thin films (oil on the water surface, soap bubble etc.). Due to quarantine I have no opportunity to use any interferometers and other laboratory technics, so the experiment should be fully "home-made". I would appreciate if anybody gave a hint, how to accomplish this.
Thanks in advance.
Thin film thickness is usually measured by spectroscopic ellipsometry (interferometry). You may rather think about the reflection color to estimate the thickness of thin films of specific (known) materials. We use this method to estimate the thickness of )or depth) of shallow semiconductor junctions
Dear Alina! If you try to make an experiment from the answer of Artur Braun, you should see rainbow stripes on the soap film when you hold it vertically and look through it. The upper stripe you see should be violet because at the upper end the film is thinner. The upper violet stripe means that at that point the thickness of the film is half of the violet light wavelength divided by 1.34 (approximate refractive index of water with soap). The next from the top violet stripe is seen at the point where the film thickness is two wavelengths of violet light divided by 1.34. And so on … If you look not through the film but at the light reflected from the film the upper violet line will be seen at the thickness 3/4 of the violet wavelengths divided by 1.34. The next one -- at the thickness 5/4 of the violet wavelengths divided by 1.34. And so on …
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