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Material dispersion can be a desirable or undesirable effect in optical applications. The dispersion of light by glass prisms is used to construct spectrometers and spectroradiometers. However, in lenses, dispersion causes chromatic aberration, an undesired effect that may degrade images in microscopes, telescopes, and photographic objectives.
Bright light therapy is a common treatment for seasonal affective disorder and for circadian rhythm sleep disorders The elderly frequently cite depression as a notable ailment. Many researchers have linked the depression to seasonal affective disorder (SAD), and seasonal mood variations have been linked to lack of light.
This is a result of the prism material's index of refraction varying with wavelength (dispersion). Generally, longer wavelengths (red) undergo a smaller deviation than shorter wavelengths (blue). The dispersion of white light into colors by a prism led Sir Isaac Newton to conclude that white light consisted of a mixture of different colors.
In optics, a diffuser (also called a light diffuser or optical diffuser) is any material that diffuses or scatters light in some manner to transmit soft light.Diffused light can be easily obtained by reflecting light from a white surface, while more compact diffusers may use translucent material, including ground glass, teflon, opal glass, and greyed glass.
Dispersive prisms are used to break up light into its constituent spectral colors because the refractive index depends on wavelength; the white light entering the prism is a mixture of different wavelengths, each of which gets bent slightly differently. Blue light is slowed more than red light and will therefore be bent more than red light.
The dispersion staining is an analytical technique used in light microscopy that takes advantage of the differences in the dispersion curve of the refractive index of an unknown material relative to a standard material with a known dispersion curve to identify or characterize that unknown material. These differences become manifest as a color ...
[1] [2] It is caused by dispersion: the refractive index of the lens elements varies with the wavelength of light. The refractive index of most transparent materials decreases with increasing wavelength. [3] Since the focal length of a lens depends on the refractive index, this variation in refractive index affects focusing. [4]
In optics, group-velocity dispersion (GVD) is a characteristic of a dispersive medium, used most often to determine how the medium affects the duration of an optical pulse traveling through it. Formally, GVD is defined as the derivative of the inverse of group velocity of light in a material with respect to angular frequency , [ 1 ] [ 2 ]