Extinction coefficient refers to several different measures of the absorption of light in a medium:
- In chemistry, biochemistry, molecular biology, or microbiology, the mass extinction coefficient and the molar extinction coefficient are parameters defining how strongly a substance absorbs light at a given wavelength, per mass density or per molar concentration, respectively.
- In physics, the "extinction coefficient" is the imaginary part of the complex index of refraction, which also relates to light absorption.
(For the quantitative relationship between the chemistry and physics definitions, see Mathematical descriptions of opacity.)
Famous quotes containing the word extinction:
“I wish all men to be free. I wish the material prosperity of the already free which I feel sure the extinction of slavery would bring.”
—Abraham Lincoln (1809–1865)