In physics, specifically statistical mechanics, a population inversion occurs when a system (such as a group of atoms or molecules) exists in a state with more members in an excited state than in lower energy states. The concept is of fundamental importance in laser science because the production of a population inversion is a necessary step in the workings of a standard laser.
Read more about Population Inversion: Boltzmann Distributions and Thermal Equilibrium, The Interaction of Light With Matter, Selection Rules, Creating A Population Inversion, Other Methods of Creating A Population Inversion
Famous quotes containing the word population:
“The population of the world is a conditional population; these are not the best, but the best that could live in the existing state of soils, gases, animals, and morals: the best that could yet live; there shall be a better, please God.”
—Ralph Waldo Emerson (1803–1882)