Stokes operators, angular momentum and radiation phase

Abstract

We present a development of a method determining the quantum phase of radiation via the conservation of the angular momentum. It is shown that a set of generalized Stokes operators can be obtained with the aid of integrals of motion and two of them determine the radiation cosine and sine of the phase which corresponds to the azimuthal phase of the angular momentum according to the construction. We compare the evolution of the radiation cosine and sine and that for the conventional phase difference in the Jaynes-Cummings model. Although the expectation values coincide in some important cases, there is a striking difference between the behaviours of variances.