Generation of a beam with a dark focus surrounded by regions of higher intensity: the optical bottle beam

A computer-generated hologram is used to form an optical beam with a localized intensity null at its focus. The beam is a superposition of two Laguerre-Gaussian modes that are phased so that they interfere destructively to give a beam focus that is surrounded in all directions by regions of higher intensity. Beams of this kind will have applications in the optical trapping of macroscopic objects or atoms; hence the term optical bottle beam. (C) 2000 Optical Society of America OCIS codes: 140.3300, 090.1760.