We observed an optical cusp diffraction catastrophe with an initially smooth but elongated Gaussian beam with an aspect ratio of 2:1. Nonlinear and linear diffraction regimes account for the near-field elliptical annulus and the far-field spatially complex astroid.
© 1999 Optical Society of America
A. M. Deykoon, M. S. Soskin, and G. A. Swartzlander, Jr., "Nonlinear optical catastrophe from a smooth initial beam," Opt. Lett. 24, 1224-1226 (1999)