[jeffreyH (OP)]

We have a spectrum defined for light which ranges in energy. Does the energy of a particular photon have a field based on its initial energy level? If so does the overlap of photon fields of varying energies cause the production of virtual particles? Would these particles then have an infinite number of energy levels due to the infinite combination of potential energies of the photons that may overlap? Is this not just another description of the background vacuum fluctuations?