I have several questions in quantum optics or the quantum theory of radiaition. I begin by the following three questions: How can a DC field ( static field) be constructed using photons ?? If the spin of photons is related to circular polarization of the constructing fields. How can linear polarized fields be constructed using photons. What is the temporal and spatial exension of photons? The single photon number state makes the spatial extension of the photon bounded only by the dimensions of the cavity in which we quantize the field !!