We discuss two types of optical processing using vortex-producing angular phase plates. In the most common spatial-filtering operation, an input object is Fourier transformed (either by Fraunhofer diffraction or with a lens system). The Fourier transform is then multiplied by an angular phase pattern, and the product is again Fourier transformed. The output is a space-invariant, edge-enhanced version of the input object. Alternatively we can directly image the object using a lens multiplied by the angular phase. The space-variant image is severely distorted along the optical axis of the system. We encode the phase plates onto a liquid-crystal display and present experimental results on both systems.
© 2004 Optical Society of America
Karlton Crabtree, Jeffrey A. Davis, and Ignacio Moreno, "Optical Processing with Vortex-Producing Lenses," Appl. Opt. 43, 1360-1367 (2004)