A reciprocity inequality is derived, involving the effective size of a planar, secondary, Gaussian Schell-model source and the effective angular spread of the beam that the source generates. The analysis is shown to imply that a fully spatially coherent source of that class (which generates the lowest-order Hermite–Gaussian laser mode) has certain minimal properties.
© 2000 Optical Society of America
(030.1640) Coherence and statistical optics : Coherence
Ari T. Friberg, Taco D. Visser, and Emil Wolf, "A reciprocity inequality for Gaussian Schell-model beams and some of its consequences," Opt. Lett. 25, 366-368 (2000)