Characteristics of three types of photon used in the descriptions of optical experiments demonstrating the properties of light are discussed: C-photon – a quasi-monochromatic electromagnetic radiation localized in space, M-photon – a hypothetical elementary particle of the light field, and Q-photon – an objective entity corresponding to the Fock state of the light field. Some properties of superfluid 3Не-В are analyzed and equations are derived describing a vortex-wave process in the medium similar to superfluid 3Не-В. The comparison of the properties of light and those of vortex-wave process in the medium similar to superfluid 3Не-В shows that there is an analogy between the properties of light and the properties of the process. The analogy found allows one to offer a physical model describing such properties of light as the constancy of its speed in inertial frames of reference, and quantum correlations of photons.

photon, speed of light, quantum correlations, spin supercurrent, superfluid physical vacuum, vortex-wave process