Complex Permittivity
In nonattenuating media, the permittivity and refractive index are related by:
- (SI), (cgs)
where is the permeability and is the permittivity. In attenuating media, the same relation is used, but the permittivity is allowed to be a complex number, called complex permittivity:
- (SI), (cgs).
Squaring both sides and using the results of the previous section gives:
(this is in SI; in cgs, drop the and ).
This approach is also called the complex dielectric constant; the dielectric constant is synonymous with in SI, or simply in cgs.
Read more about this topic: Mathematical Descriptions Of Opacity
Famous quotes containing the word complex:
“In ordinary speech the words perception and sensation tend to be used interchangeably, but the psychologist distinguishes. Sensations are the items of consciousness—a color, a weight, a texture—that we tend to think of as simple and single. Perceptions are complex affairs that embrace sensation together with other, associated or revived contents of the mind, including emotions.”
—Jacques Barzun (b. 1907)