{"term":{"id":"08650","title":"optical absorption depth","longtitle":"IUPAC Gold Book - optical absorption depth","doi":"10.1351\/goldbook.08650","code":"08650","status":"current","definitions":[{"id":1,"text":"Depth in a sample at which the intensity of an incident beam is reduced to \\(1\/\\rm{e}\\) of its value at the surface of the sample.","notes":{"1":"\\(\\mu_{\\beta}\\) is the reciprocal of the linear Napierian absorption coefficient.","2":"SI unit: \\(\\pu{m}\\). Common unit: \\(\\pu{\\upmu m}\\)."},"links":[{"term":"linear Napierian absorption coefficient","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08265"}],"sources":["PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 757 (https:\/\/doi.org\/10.1515\/pac-2019-0203)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/08650\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/08650\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/08650\/plain"},"citation":"Citation: 'optical absorption depth' 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.08650","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":"2026-05-30T11:32:45+00:00"}}