Chromatic Dispersion - Definition and Applications

Chromatic dispersion is the change in refractive index due to a change in wavelength. Dispersion is the phenomenon that causes light to be separated into various colors while passing through a prism.

Dispersion is sometimes referred to as chromatic dispersion, in order to describe the wavelength dependency. Dispersion is not specific to light waves alone; it may be considered for any wave that traverses through in-homogenous media.

Basic Principle

Dispersion of a medium is expressed in terms of the Abbe’s number, or the V number. There are two types of dispersion: material and waveguide dispersion. The former occurs due to the frequency dependency of the medium, and the latter due to the change in speed of a wave in a waveguide.

Dispersion may be desirable or undesirable in optical applications. For some applications, dispersion may be useful for the working of optical instruments, such as spectrometers and spectroradiometers. In the case of lenses, dispersion causes chromatic aberration, which affects the quality of images.

Applications

Some of the applications of chromatic dispersion are below:

• Gemological analysis
• Waveguides
• Spectrometers and spectroradiometers

References

• Dispersion – Georgia State University
• A chromatic Dispersion estimation method for arbitrary modulation formats – University of Texas