The study of pixelated sampling and its influences on the 2nd-order spatial coherence measurement

Abstract

Since the measurement of spatial coherence requires multiple sampling to acquire the complex coherence factor of a wavefield, it is convenient to accomplish such dynamic work by a non-redundant multi-slit through a programmable device such as spatial light modulator (SLM). In this study, we examined the influence of SLM-like pixelated structure, parameterized by whose fill factor, on both intensity distribution (first-order statistics) and complex coherence factor (second-order statistics). Based on the generalized Van Cittert-Zernike theorem that as the source satisfied the quasi-homogeneous condition, the coherence factor of the wavefield was irrelevant to the pixelated sampling structure. The inference was validated by a SLM-based experiment from a pseudothermal light source. We expected this work to be useful for future dynamic coherence measurement.