Search Menu
Photonics Media Photonics Marketplace Photonics Spectra BioPhotonics Vision Spectra Photonics Showcase Photonics ProdSpec Photonics Handbook
Photonics Dictionary


1. The decrease of the absorption (or gain) coefficient of a medium near some transition frequency when the power of the incident radiation near that frequency exceeds a certain value. As long as the absorption (or gain) coefficient is constant, the power absorbed (or emitted) by the medium is proportional to the incident power. However, there is always a limit to the rate at which the medium can absorb (or emit) power that is determined by the lifetimes of the energy levels involved. As this limit is reached, the induced transitions become rapid enough to affect the energy level populations, making them more nearly equal. 2. With respect to color, attribute of a visual sensation that permits a judgment to be made of the proportion of pure chromatic (in contrast to achromatic) color in the total sensation. The psychosensorial correlate, or nearly so, of colorimetric purity. See also chroma; Munsell chroma.
back to top
Facebook Twitter Instagram LinkedIn YouTube RSS
©2023 Photonics Media, 100 West St., Pittsfield, MA, 01201 USA, [email protected]

Photonics Media, Laurin Publishing
x We deliver – right to your inbox. Subscribe FREE to our newsletters.
We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.