Measurement of spatial coherence of light [Invited]

Abstract

The most frequently used experimental techniques for measuring the spatial coherence properties of classical light fields in the space–frequency and space–time domains are reviewed and compared, with some attention to polarization effects. In addition to Young’s classical two-pinhole experiment and several of its variations, we discuss methods that allow the determination of spatial coherence at higher data acquisition rates and also permit the characterization of lower-intensity light fields. These advantages are offered, in particular, by interferometric schemes that employ only beam splitters and reflective elements, and thereby also facilitate spatial coherence measurements of broadband fields.

Experimental measurement of complex elements of correlation matrix of polarized light

“…Such correlation function is a complex quantity and complete measurement of all four elements of the matrix is required to characterize the vector beam. Various techniques have been developed for the measurement of two-point correlation functions of the vector beam [20][21][22][23][24]. Majority of these techniques are based on Young's interference, relying on field-based interferometer and point scanning.…”

Effect of Polarization on Cross-Spectral Density Matrix

“…Additionally, sequential scanning for point sampling is extremely time consuming. Alternative methods relying on the concept of Young's approach have been developed to address some of these limitations [48,49]. Another method based on the Hanbury Brown-Twiss (HBT) experiment was introduced for random vector light fields following Gaussian statistics.…”