The spatial correlation properties in the geometrical focal region of a converging, partially coherent vortex wave field are analyzed. Expressions are derived for a pair of points on the axis of symmetry and for a pair of points in the focal plane. It is found that the longitudinal and transverse coherence lengths in the focal region change with the variation of the topological charge and the normalized coherence length of the vortex field. In addition, the degree of coherence is shown to possess phase singularities.
© 2007 Optical Society of America
Coherence and Statistical Optics
Original Manuscript: November 27, 2006
Manuscript Accepted: February 22, 2007
Published: July 11, 2007
Lianzhou Rao and Jixiong Pu, "Spatial correlation properties of focused partially coherent vortex beams," J. Opt. Soc. Am. A 24, 2242-2247 (2007)