Synthesis of spatial coherence

The mutual intensity function plays a major role ill characterizing quasi-m onochromatic, partially coherent optical signals. We propose to use the mut ual intensity as a carrier of information to avoid speckle noise in coheren t illumination systems and to permit the use of complex functions that are prohibited spatially incoherent sources. To do this we require methods for encoding the information as a coherence function. An optical system for syn thesizing a beam with a given mutual intensity function is proposed. The op tical system permits the synthesis of any desired mutual intensity function . The illumination is supplied by a quasi-monochromatic, spatially incohere nt source. Experimental results demonstrate the performance of this system for several cases. (C) 1999 Optical Society of America.