Relation between Bandwidth and Spatial Coherence in Experiments Involving Dispersion

In the study of a flexible fluid prism, it was noticed that the coherence of a collimated beam arising from a filtered Hg lamp (Δν≤100 Å) was greatly reduced, even for prism angles of only a few degrees (7° or less). A mathematical description for the effect of thin prisms on the coherence was accordingly developed and used as a guide to further study of the effect. This description, as well as the confirming experimental results, is presented in this paper.