PHYS 131 Lecture Notes - Lecture 6: Diffraction Grating, Refraction, Photon
14 Nov 2017
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Document Summary
One wave of property of light waves is dispersion. Dispersion: the separation and spreading out of colors as a ray of white light passes through a prism (or diffraction grating). In a prism, dispersion occurs because colors of light have different wavelengths and speeds in denser media. Blue rays have the shortest wavelengths and, therefore, slow the most and bend the most. Red slows the least and bends the least. Glass and other transparent materials have a resonance frequency in the uv region. As the frequency of a photon approaches the resonance frequency (uv) there is a greater and greater interaction (resonance) with the atoms of the medium. For example, blue photons are not absorbed, but are detained momentarily as they pass by each atom. Frequencies with a larger deviation from the resonance frequency, such as red photon frequencies, interact less and thus are detained for less time.
