# thin-film interference

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Interference and Colour, Part II - Thin Film Interference Keywords: absorption, colour, diffraction grating, index of refraction, inherent phase difference, interference, light, path length difference, phase, phase difference, phase shift, reflection, thin-film interference, transmission, waves

What does this beetle and a soap bubble have in common?

This article explains how by having a thin-film the waves reflecting off of the boundaries between media can interfere and result in coloration.

7 years 19 weeks ago
Interference and Colour, Part I - Diffraction Gratings Keywords: absorption, colour, diffraction grating, index of refraction, inherent phase difference, interference, light, path length difference, phase, phase difference, phase shift, reflection, thin-film interference, transmission, waves

What gives this beetle its rainbow colours?

This article describes how colouration of an object can arise due to interference of the light waves being reflected from the object.
Periodically arranged structures which act as point sources are one means of creating the condition that at certain angles only one specific wavelength will interfere constructively. The wavelengths that interfere constructively determine the colour of the object.
Examples of colouration in beetles by interference due to periodic structures is given.

7 years 27 weeks ago
Interference and Colour Part III - Mathematics of Thin-Film Interference Keywords: absorption, colour, diffraction grating, index of refraction, inherent phase difference, interference, light, path length difference, phase, phase difference, phase shift, reflection, thin-film interference, transmission, waves

How can alternating layers in a beetle's shell give the beetle brilliant colour?

This article explains how to derive the conditions for constructive interference for thin-film interference and finds the thicknesses of alternating layers of melanin and protein to give constructive interference at 635 nm.

7 years 17 weeks ago

C21: Physics Teaching for the 21st Century
UBC Department of Physics & Astronomy
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