You seem to be talking about visible light waves. When a physicist talks about light waves in general, he is talking about the entire spectrum of EM waves from the lowest frequency to the highest frequency. RF waves are part of the spectrum of invisible light. The energy in each RF photon is easy to calculate: Photon Energy = h*f where h is Planck's constant and f is the frequency. h = 6.626x10^-34 joules/sec. So the energy in an individual RF photon at 10.125 MHz would be: 10.125 MHz Photon Energy = 6.708825x10^-27 joules At 100 watts (joules/second) on 10.125 MHz, I am radiating approximately 149,057,398,300,000,000,000,000,000 photons per second. The only difference in 10.125^6 Hz RF and 10.125^15 Hz visible light is frequency.