Saturated absorption: instanteneous, or does it produce lasting effects?

[franco1991]

In terms of saturated absorption of EM waves, is the following correct?:

The material only has so many atoms that can absorb photons, so if there are more photons that there are atoms, the atoms cannot absorb all the photons, and thus a certain percentage of the photons pass through.

OR alternatively is it that all the atoms becomes excited, and the time it takes to re-emit the photons increases, such that SUBSEQUENT application of photons results in less absorption.


Additional details:

If the first is correct, that there aren't enough atoms to absorb every photon, then could one not decrease the intensity of light required to reach saturated absorption in a material by decreasing the number of atoms (in the wave's path) rather than increasing the intensity of the EM wave?

 

[Valerie Park]

Yes, this is correct. Decreasing the number of atoms in the wave's path will reduce the intensity of light required to reach saturated absorption in a material. Alternatively, increasing the intensity of the EM wave can also result in saturated absorption if there are enough atoms available to absorb all of the photons.