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Radiant Flux

Author: the photonics expert

Definition: radiant energy per unit time which is emitted, transmitted, reflected or received by an object

Alternative terms: radiant power, optical power

Categories: article belongs to category general optics general optics, article belongs to category light detection and characterization light detection and characterization, article belongs to category optical metrology optical metrology

Units: W

Formula symbol: <$\Phi_\textrm{e}$>

DOI: 10.61835/rkw   Cite the article: BibTex plain textHTML

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.

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I would like to find the power per unit area reached.

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Look for irradiance or optical intensity. (Radiant intensity is something different.)

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