Radiant Flux
Author: the photonics expert Dr. Rüdiger Paschotta (RP)
Definition: radiant energy per unit time which is emitted, transmitted, reflected or received by an object
Alternative terms: radiant power, optical power
Categories:
Units: W
Formula symbol: <$\Phi_\textrm{e}$>
DOI: 10.61835/rkw Cite the article: BibTex plain textHTML Link to this page LinkedIn
The radiant flux is a term of radiometry. It is defined as the radiant energy per unit time which is emitted, transmitted, reflected or received by an object. In the case of light, it is also simply called the optical power. However, the term radiant flux can be used for any kinds of electromagnetic radiation, including e.g. X-rays, ultraviolet light, infrared light and terahertz radiation.
A related quantity is the spectral flux, defined as the radiant flux per unit frequency or wavelength interval. The units are then W/Hz or W/nm, for example.
More to Learn
Encyclopedia articles:
2020-05-23
I would like to find the power per unit area reached.
The author's answer:
Look for irradiance or optical intensity. (Radiant intensity is something different.)