Quantum phase measurements and non-classical polarization states of light

In our paper we consider the non-classical behaviour of both the Hermitian (observable) Stokes parameters of light and the phase difference of two mod es that describe the quantum polarization states of optical field. To chara cterize the degree of polarization of light we introduce a new quantity tak ing into account the quantum properties of different quantum states of two orthogonally polarized modes. The problem of determination of the phase dif ference in two modes of optical field for the quantum polarization states o f light is discussed. To describe in general such a quantum field we introd uce two pairs of the phase operators: the phase angles for the Stokes param eters of light in a three-dimensional picture of the Poincare sphere. We al so consider a special type of the eight-port polarization interferometer (p olarimeter) for simultaneous homodyne detection of both the Stokes paramete rs of light and the polarization phase operators and their fluctuations as well. Using an anisotropic (spatioperiodic) Kerr-like nonlinear medium asso ciated with the polarization interferometer we could generate and also obse rve the polarization-squeezed phase states of light. The fluctuations in th e phase difference between two orthogonally polarized modes for these non-c lassical states are less than the fluctuations for light in coherent state.