Hi, I'm trying to find out why stimulated emission (creation of an identical photon) doesn't violate the no-cloning theorem. There are lots of different opinions on this on the internet, e.g. "the second photon is not exactly identical, the energy is slightly different" or "since stimulated emission only works for a certain frequency, it doesn't copy general states". However, those explanations don't say anything about the polarization. If it were possible to copy a general polarization (even with a small error), one could build a superluminal communication device. The most convincing explanation I've found is that spontaneous emission disturbs the process just enough such that copies are "imperfect enough" so they cannot be used for superluminal communication. Can anyone confirm this?