Projection of diffraction patterns for use in cold-neutral-atom trapping

Abstract

Scalar diffraction theory is combined with beam-propagation techniques to investigate the projection of near-field diffraction patterns to spatial locations away from the aperture for use in optically trapping cold neutral alkali-metal atoms. Calculations show that intensity distributions with localized bright and dark spots usually found within a millimeter of the diffracting aperture can be projected to a region free from optical components such as a cloud of cold atoms within a vacuum chamber. Calculations also predict that the critical properties of the optical dipole atom traps are not only maintained for the projected intensity patterns but also can be manipulated and improved by adjustment of the optical components outside the vacuum chamber.

Two-dimensional lattice of blue-detuned atom traps using a projected Gaussian beam array

“…Projected arrays of dipole traps have been demonstrated using either microlenses [12], holographic methods [13], or diffractive optics [14,15]. Several experiments in recent years have demonstrated loading of single atoms into small arrays of optical traps [13,14] and into larger optical lattices using either stochastic loading [16] or Bose-Einstein condensate to Mott insulator techniques [17][18][19].…”