Photon structure and wave function from the vector potential quantization

International audience; A photon structure is advanced based on the experimental evidence and the vector potential quantization at a single photon level. It is shown that the photon is neither a point particle nor an infinite wave but behaves rather like a local "wave-corpuscle" extended over a wavelength, occupying a minimum quantization volume and guided by a non-local vector potential real wave function. The quantized vector potential oscillates over a wavelength with circular left or right polarization giving birth to orthogonal magnetic and electric fields whose amplitudes are proportional to the square of the frequency. The energy $\hbar$$\omega$ and momentum $\hbar$$\bar{k}$ are carried by the local wavecorpuscle guided by the non-local vector potential wave function suitably normalized.