{"term":{"id":"05060","title":"radiative absorption","longtitle":"IUPAC Gold Book - radiative absorption","doi":"10.1351\/goldbook.R05060","code":"R05060","status":"current","also defines":"<em>also defines<\/em>: transition probability for absorption, transition probability for stimulated emission","definitions":[{"id":1,"text":"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.","contexts":[],"links":[{"term":"absorption","url":"https:\/\/goldbook.iupac.org\/terms\/view\/A00036"},{"term":"absorption line","url":"https:\/\/goldbook.iupac.org\/terms\/view\/A00041"},{"term":"excited state","url":"https:\/\/goldbook.iupac.org\/terms\/view\/E02257"},{"term":"ground state","url":"https:\/\/goldbook.iupac.org\/terms\/view\/G02704"},{"term":"probability","url":"https:\/\/goldbook.iupac.org\/terms\/view\/P04855"},{"term":"radiative de-excitation","url":"https:\/\/goldbook.iupac.org\/terms\/view\/R05062"},{"term":"spectral radiant energy","url":"https:\/\/goldbook.iupac.org\/terms\/view\/ST07480"},{"term":"stimulated emission","url":"https:\/\/goldbook.iupac.org\/terms\/view\/S06015"}],"sources":["PAC, 1985, 57, 1453. 'Nomenclature, symbols, units and their usage in spectrochemical analysis - V: Radiation sources (Recommendations 1985)' on page 1463 (https:\/\/doi.org\/10.1351\/pac198557101453)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/R05060\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/R05060\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/R05060\/plain"},"citation":"Citation: 'radiative absorption' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351\/goldbook.R05060","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2026-06-28T12:26:45+00:00"}}