# spectral flux density

> quantity that describes the rate at which energy is transferred by electromagnetic radiation through a real or virtual surface, per unit surface area and per unit wavelength (or, equivalently, per unit frequency)

**Wikidata**: [Q7575193](https://www.wikidata.org/wiki/Q7575193)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Spectral_flux_density)  
**Source**: https://4ort.xyz/entity/spectral-flux-density