radiative absorption

in spectrochemistry
Also contains definitions of: transition probability for absorption, transition probability for stimulated emission
https://doi.org/10.1351/goldbook.R05060
A process by which a particle in the
ground state
or an
excited state
may undergo transition to a higher energy level by
absorption
of a photon. For a given particle in the lower state of
probability
per second of such a transition in a field with a continuous spectrum is proportional to the
spectral radiant energy
density of the
absorption line
. The proportionality constant is termed the transition
probability
for absorption. The transition
probability
for
stimulated emission
is defined in a similar way for the reverse
radiative de-excitation
process that is induced by the same radiation field.
Source:
PAC, 1985, 57, 1453. (Nomenclature, symbols, units and their usage in spectrochemical analysis - V: Radiation sources (Recommendations 1985)) on page 1463 [Terms] [Paper]