Hyperbolic umbilic caustics from oblate water drops with tilted illumination: Observations

摘要

Highlights?Light scattering observed in the primary rainbow region of water oblate drops.?The drops are acoustically levitated with a horizontal equatorial plane.?The illumination may be vertically tilted by a small angle.?The drop aspect ratio for a hyperbolic-umbilic focal section depends on tilt.?The location of the V-shaped HUFS caustic depends on tilt.?A related application of numerical ray-tracing is summarized.AbstractVarious groups have reported observations of hyperbolic umbilic diffraction catastrophe patterns in the far-field scattering by oblate acoustically levitated drops with symmetric illumination. In observations of