What is the constructive interference of light

Wave optics

Light dispersion¶

The speed of propagation of light in an optical medium is not only dependent on its refractive index, but also on the light frequency. The different spectral components are refracted to different degrees when passing through a prism, so that white light can be divided into its color components by means of a prism. [3]

Technically, this principle of spectral decomposition can be used in two ways:

  • In the case of a “monochromator”, a screen with a narrow opening is attached instead of a screen. As a result, only a narrow area (quasi a single color) of the spectrum is filtered out of the light spectrum for further test purposes.
  • With a "ref:Prism spectrometer “The light components of the spectrum are compared with the light components of known light sources using a scale. A comparatively simple calibration as with an optical grating is not possible, however, since the dispersion is not linearly related to the light frequency or the wavelength.

In the case of a prism, the functional principle of which is based on the dispersion of light, blue light is deflected more strongly from the original direction than red light; it is exactly the opposite with an optical grating. Another difference between these two types of spectral generation is that a prism as opposed to an optical grating only a Spectrum generated, which is, however, more light-intensive than the individual grating spectra.

For spectral analysis, however, grids are generally preferred, on the one hand because they are easier to calibrate, but above all because of the greater fanning out or the better "resolution" when viewing the individual spectral lines.


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