If a full energy photon that has this virtue that can be converted to two particles with different electric charges and all photons independent of their frequencies, carry electromagnetic energy. This virtue of electromagnetic energy must be investigated in electric and magnetic fields dependent to photon that can be converted to electron and positron with different electric charges.
https://www.researchgate.net/publication/303988070_Generalization_of_the_Dirac%27s_Equation_and_Sea
http://gsjournal.net/Science-Journals/Research%20Papers/View/6552
Article Generalization of the Dirac's Equation and Sea