Why does the angle of light through a prism change based on its wavelength?

In summary, the angle deviation of light passing through a prism is inversely related to its wavelength, with a 1/x graph. This is likely due to the shorter deflected path compared to the undeflected path, with a longer path corresponding to a bigger wavelength. The ordinary dispersion relation in materials like silica is caused by strong absorption in the ultraviolet region, linked to the energy band gap of the material. The Kramers-Kronig relations provide the analytical form for this phenomenon.
  • #1
Ambidext
60
0
Just a general question on the EM spectrum.

angle deviation of the light wave as it passes through a prism seems to be inversely related (looks like a 1/x graph) to its wavelength. So my question, why?

My guess is that the deflected path is shorter than the undeflected by cos A, where
0 < A < 90
and the bigger wavelength is, the longer the path it can travel and thus a bigger wavelength corresponds to a longer path x cos A?
 
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  • #2
The ordinary dispersion relation that we observe in glasses such as silica is due to the strong absorption in the ultraviolet region (which, in turn, is due to the size of the energy band gap of the material; that is, the energy difference between the valence and conduction band).

The analytical form is given by the Kramers-Kronig relations. http://en.wikipedia.org/wiki/Kramers–Kronig_relation.

Claude.
 

FAQ: Why does the angle of light through a prism change based on its wavelength?

What is the relationship between intensity and wavelength?

The intensity of a wave is directly proportional to its wavelength. This means that as the wavelength increases, the intensity also increases. Conversely, as the wavelength decreases, the intensity also decreases.

How does the intensity of a wave affect its energy?

The intensity of a wave is directly proportional to its energy. This means that as the intensity increases, the energy of the wave also increases. This is because a higher intensity wave carries more energy per unit area.

What is the difference between intensity and amplitude?

Intensity refers to the amount of energy carried by a wave per unit area, while amplitude refers to the maximum displacement of particles in a medium from their equilibrium position. Intensity is a measure of the strength of a wave, while amplitude is a measure of its size.

How does the wavelength of a wave affect its color?

The wavelength of a wave is directly related to its color. Longer wavelengths correspond to colors on the red end of the visible light spectrum, while shorter wavelengths correspond to colors on the blue end. This is why we perceive different colors in a rainbow - each color corresponds to a different wavelength.

Why do different materials absorb or reflect different wavelengths of light?

The atomic and molecular structures of materials determine which wavelengths of light they will absorb or reflect. When light interacts with these structures, certain wavelengths are absorbed while others are reflected. This is why different materials appear to have different colors - they are reflecting different wavelengths of light.

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