https://dx.doi.org/10.1351/goldbook.R05041
Radiant power,
, emitted at all wavelengths by an element of surface containing the source point under consideration divided by the area of the source. SI unit is
.


Notes:
- Mathematical definition:
. If the radiant power
is constant over the surface area considered,
.
- Equivalent to the integration of the radiant power leaving a source over the solid angle and over the whole wavelength range. Mathematical definition:
, where
is the spectral radiant exitance at wavelength
.
- Same as spherical radiant exitance. Formerly called radiant emittance.
Source:
PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 409