Term: stray light
https://doi.org/10.1351/goldbook.08293

Definition:
Electromagnetic radiation that does not follow the usual path through a spectrometer and consequently appears in a spectrum at a frequency or wavenumber different from its initial value. The term is also used to refer to radiation that passes around the sample instead of through it, and consequently is not modified by the sample and seriously affects absolute and relative intensities.

Link: 
Related Term: electromagnetic radiation (http://doi.org/10.1351/goldbook.08242).
Related Term: spectrum (http://doi.org/10.1351/goldbook.08291).
Related Term: wavenumber (http://doi.org/10.1351/goldbook.08302).

Source: PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 675 (https://doi.org/10.1515/pac-2019-0203)

Citation: 'stray light' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.08293

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.

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