Spatial coherence measurement via a digital micromirror device based spatiotemporal light modulation.

ABSTRACT

We propose a method for measuring the spatial coherence of light by means of temporal modulation of a double slit displayed on a digital micromirror device. It is demonstrated theoretically and experimentally that the technique is generally insensitive to background light, and thus its suppression or subtraction is not necessary. Moreover, the visibility of the interference fringe pattern can be enhanced by modulating only either one of the two slits. These favorable features enable one to measure the spatial coherence of even faint light more conveniently and accurately.