optical throughput symbol: G

of a spectrometer
Synonym: étendue
https://doi.org/10.1351/goldbook.08277
Volume in phase space, a function of the area of the emitting source (S) and the solid angle into which it propagates (Ω).d2G=dSdΩ.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 669 [Terms] [Paper]
Citation: 'optical throughput' 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.08277 RIS BibTex EndNote
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