So reading more about this: http://en.wikipedia.org/wiki/Photon_gas , it looks like a scenario where a blackbody container was created, with a Boltzmann "temperature" peak equal to the energy level of the incident photons. Thus, all absorbed photons would be re-emitted at with the same distribution as the blackbody walls. And apparently, this phenomenon was tested in an ultra-low temperature scenario.

Still, I wonder. Given the low temperatures, the Boltzmann distribution suggests photons in the microwave or lower frequencies.