Radiation phase and Stokes parameters

The approach which has been proposed by one of us [Optics Comm. 136 (1997) 219] is developed. The quantum phase properties of radiation are determined via the conservation of the angular momentum in the interaction with a source. It is shown that the use of two dual representations of the angular momentum of the dipole transition leads to the definition of five operators similar in some sense to the Stokes operators of the radiation. The approach is compared with that by Pegg and Barnett [20]. (C) 1998 Elsevier Science B.V.