Two-point Stokes parameters: interpretation and properties

Abstract

Whereas the classic Stokes parameters are measures of intensity, the recently introduced two-point Stokes parameters characterize spatial coherence. It is shown that in analogy to the Stokes parameters, the two-point parameters have a physical interpretation as sums and differences of (scalar) cross-spectral density functions of specific electric-field components. A measurement scheme and several physical consequences of the two-point parameters are discussed.