Abstract

This talk is a somewhat more sophisticated version of the expository article of Tape (1982), with added technical flesh and more halos, both real and theoretical. The message is the same: Most refraction halos are physical manifestations of singularities of mappings, and the crude nature of these halos is anticipated by singularity theory. Infralateral arcs, supralateral arcs, and upper and lower tangent arcs tend to be "folds," while many Lowitz arcs have "pleats" as well as folds. The circular halos are instances of a higher dimensional singularity.

© 1983 Optical Society of America