Dynamics of Two-State Systems: Time-Varying Polarization Devices

The problem of the time-varying polarization devices is analyzed in the general frame of the dynamics of the two-state systems. A vectorial and pure operatorial Pauli algebraic approach, conjugated with a Poincaré geometric one is adopted. The general equation of evolution of the density operator of the light polarization state interacting with a time-varying birefringent device is established this way and applied in analyzing the modification of the polarization and spectral structure of light by modulation.