photon flow, $$\mathit{\Phi} _{\text{p}}$$

https://doi.org/10.1351/goldbook.P04633
The number of photons (quanta, $$N$$) per unit time. ($$\frac{\text{d}N}{\text{d}t}$$, simplified expression: $$\mathit{\Phi} _{\text{p}} = \frac{N}{t}$$ when the number of photons is constant over the time considered). The SI unit is $$\text{s}^{-1}$$. Alternatively, the term can be used with the amount of photons (mol or its equivalent @E01914@), the SI unit then being $$\text{mol s}^{-1}$$.
See:
spectral photon flow