We generate helical Ince–Gaussian (HIG) beams by using complex amplitude and phase masks encoded onto a liquid-crystal display (LCD). These beams display an intensity pattern consisting of elliptic rings, whose number and ellipticity can be controlled, and a phase exhibiting a number of in-line vortices, each with a unitary topological charge. We show experimental results that display the properties of these elliptic dark hollow beams. We introduce a novel interference technique for generating the object and reference beams by using a single LCD and show the vortex interference patterns. We expect that these HIG beams will be useful in optical trapping applications.
© 2006 Optical Society of America
(050.1970) Diffraction and gratings : Diffractive optics
(100.5090) Image processing : Phase-only filters
(140.3300) Lasers and laser optics : Laser beam shaping
(230.6120) Optical devices : Spatial light modulators
Diffraction and Gratings
Joel B. Bentley, Jeffrey A. Davis, Miguel A. Bandres, and Julio C. Gutiérrez-Vega, "Generation of helical Ince-Gaussian beams with a liquid-crystal display," Opt. Lett. 31, 649-651 (2006)