Calculate constructive and destructive interference conditions in thin films like soap bubbles or oil slicks.
Film & Light Parameters
n
nm
- OR -
nm
Calculation Results
Enter index and thickness/wavelength
About this calculator
Quick Reference
nRefractive Index
dFilm Thickness
λWavelength
mInteger (0, 1, 2...)
Overview
Thin-film interference occurs when light waves reflecting off the top and bottom surfaces of a thin film interfere with each other. This creates the colorful patterns seen in soap bubbles and oil slicks.
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Pro Tips
Visible light ranges from approx 400 nm (violet) to 700 nm (red).
Soap water has a refractive index approx 1.33.
A phase shift occurs when light reflects from a medium with a higher refractive index.
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Fun Facts
"The colors of a peacock's feathers are not due to pigments but to thin-film interference in their structures."
"Anti-reflective coatings on glasses use thin-film interference to cancel out reflections."
"A soap bubble's wall is about 1,000 times thinner than a human hair when it shows bright colors."
