Measurements of spatial coherence of partially coherent light with and without orbital angular momentum.
We study the spatial coherence of a partially coherent beam before and after being transmitted through a spiral phase plate that changes the overall orbital angular momentum of the field. The two-point coherence function is measured and directly visualized on a CCD through interference in a Mach-Zehnder interferometer equipped with an image rotator. We show, in particular, how the coherence singularities associated with Airy rings are strongly affected by the spiral phase plate.
Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands. pires@molphys.leidenuniv.nl
H Di Lorenzo
HD
Pires
J
J
Woudenberg
M P
MP
van Exter