Extinction coefficient
# Extinction coefficient

Extinction coefficient refers to several different measures of the absorption of light in a medium:

* Attenuation coefficient, sometimes called "extinction coefficient" in meteorology or climatology
   * Mass extinction coefficient, how strongly a substance absorbs light at a given wavelength, per mass density
   * Molar extinction coefficient, how strongly a substance absorbs light at a given wavelength, per molar concentration
* Optical extinction coefficient, the imaginary part of the complex index of refraction
