Interpretation and experimental demonstration of twisted Gaussian Schell-model beams

The twisted Gaussian Schell-model (GSM) beams, recently introduced by Simon and Mukunda [ J. Opt. Soc. Am. A9, 95 ( 1993)], are interpreted in physical-optics terms by decomposition of such beams into weighted superpositions of overlapping, mutually uncorrelated but spatially coherent component fields. The decomposition provides considerable physical insight into the propagation characteristics of the twisted GSM beams and also suggests convenient practical methods for generating these novel wave fields. Key properties of the twisted GSM beams are demonstrated experimentally by use of an acousto-optic coherence control technique to supply the necessary partially coherent fields.