Term: radiant power, P
https://doi.org/10.1351/goldbook.R05046

Definition:
power emitted, transferred or received as radiation. SI unit is J s-1 = W.

Notes:
0) Mathematical definition: P = dQ/dt. If the @R05039@ Q is constant over the time interval, P = Q/t.
1) In @R05115@, flux  (Φ) is used with the same units as P. The symbol Φ is reserved for @Q04991@ in @P04588@. Therefore, the use of flux (Φ) is not recommended.

Related Terms:
1) radiant energy (http://doi.org/10.1351/goldbook.R05039).
2) radiometry (http://doi.org/10.1351/goldbook.R05115).
3) quantum yield (http://doi.org/10.1351/goldbook.Q04991).
4) photochemistry (http://doi.org/10.1351/goldbook.P04588).
5) power (http://doi.org/10.1351/goldbook.P04792).

Source: PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 410 (https://doi.org/10.1351/pac200779030293)

Citation: 'radiant power, P' 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.R05046

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