Abstract
Classical model of light in helicity formalism is presented. Then quantum point of view at photons -- construction and interpretation of photon wave function is proposed. Quantum mechanics of photon is investigated. The Bia\l ynicki -- Birula scalar product Ψ₁| Ψ₂_BB and the generalized Hermitian conjugation γ^+-0.45em+ of linear operator γ are discussed. Quantum description of light on a phase space is developed. A photon Wigner function is built.