Time-dependent physical Stokes parameters and degree of polarization of light

We extend the concept of the Eberly-Wodkiewicz time-dependent physical spectrum of light to electromagnetic fields by considering the observable time dependence of four appropriately defined Stokes parameters. We also define the concept of time-dependent physical degree of polarization of light by means of these parameters, and discuss the measurement of these quantities using a tunable spectral filter and a detector with a finite response time. The concepts are illustrated by examples with spectrally phase-modulated fully and partially coherent model pulse trains.