This is an excellent explaination of quantum optics. I have a few other questions about this subject. They might not seem to be important questions, but how do we know what is important. First, what is the field strength of the electric and magnetic fields of a photon? I could be wrong, but I think that all photons have the same field strength. The energy is only dependent on frequency. Thus, the field strength must be constant. I have also written on photons recently on Medium with more details. I would like to converse with you more on these subjects.