https://doi.org/10.1351/goldbook.P04633
The number of photons (quanta, ) per unit time. ( , simplified expression: when the number of photons is constant over the time considered). The SI unit is . Alternatively, the term can be used with the amount of photons (mol or its equivalent .
einstein
), the SI unit then being See:
spectral photon flow
See also:
radiant power