I don't think it's correct to think of a laser as a source in some thermal equilibrium. "Concentrating temperature" passively from sources in thermal equilibrium is forbidden, but there's nothing preventing "concentrating power".
Pulsed lasers bring material interactions into a highly non-linear regime - photon intensity is so high that multiple photon absorption is common. In the typical nuclear decay regime you are concerned with single photon absorption, and the gamma ray intuition is correct. There are also a number of approaches where various targets hit with ultrafast lasers produce controllable flux of gamma rays which are used in downstream experimentation.
Pulsed lasers bring material interactions into a highly non-linear regime - photon intensity is so high that multiple photon absorption is common. In the typical nuclear decay regime you are concerned with single photon absorption, and the gamma ray intuition is correct. There are also a number of approaches where various targets hit with ultrafast lasers produce controllable flux of gamma rays which are used in downstream experimentation.