A plot of a quantity related to the absorption (
absorbance, cross section, etc.) multiplied by the
quantum yield for the considered process against a suitable measure of photon energy, such as frequency,

, wavenumber,

, or
wavelength,

, e.g. the conversion cross section,

, has the SI unit

.
Source:
PAC, 1996, 68, 2223
(Glossary of terms used in photochemistry (IUPAC Recommendations 1996))
on page 2234
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.