We propose some new schemes to constitute two-dimensional (2D) array of multi-well optical dipole traps for cold atoms (or molecules) by using an optical system consisting of a binary 7r-phase grating and a 2D array of rectangle microlens. We calculate the intensity distribution of each optical well in 2D array of multi-well traps and its geometric parameters and so on. The proposed 2D array of multi-well traps can be used to form novel 2D optical lattices with cold atoms (or molecules), and form various novel optical crystals with cold atoms (or molecules), or to perform quantum computing and quantum information processing on an atom chip, even to realize an array of all-optical multi-well atomic (or molecular) Bose- Einstein condensates (BECs) on an all-optical integrated atom (or molecule) chip.
We investigate the diffraction characteristics of an incident Gaussian beam cut by a straight edge bounding a semi-infinite opaque plane using Kirchhoff scalar wave theory in the Fresnel limit, and propose a new and simple mirror scheme to reflect atoms by using the intensity gradient induced by a blue-detuned semi-Gaussian laser beam. The optical potential of the diffracted light of the knife-cut semi-Gaussian beam for 85 Rb atom and its spontaneous emission probability are calculated and compared with the performance of the evanescent-wave mirror. Our study shows that the optical potential of the diffracted light of the semi-Gaussian beam is far higher than that of the evanescent light wave, and the maximum normal velocity of the incident atoms can be far greater than that of the evanescent light wave under the same parameters, so the blue-detuned semioGaussian beam, as a novel atomic mirror, can be used to efficiently reflect cold atoms with a normal velocity of greater than 1 m/s. However, the intensity gradient (force) of the diffracted light of the semi-Gaussian-beam is much smaller than that of the evanescent light wave, so its spontaneous emission probability is greater than that from the evanescent-wave when the normal velocity of incident atoms is greater.
This paper proposes a scheme to guide cold polar molecules by using a single charged wire half embanked in an insulating substrate and a homogeneous bias electric field, which is generated by a plate capacitor composed of two infinite parallel metal plates. The spatial distributions of the electrostatic field produced by the combination of the charged wire and the plate capacitor and the corresponding Stark potentials (including dipole forces) for metastable CO molecules are calculated, the relationships between the electric field and the parameters of our charged-wire layout are analysed. It also studies the influences of the insulator on the electric field distribution and the discharge effect. This study shows that the proposed scheme can be used to guide cold polar molecules in the weak-field - seeking states, and to form various molecule-optical elements, such as molecular funnel, molecular beam-splitters and molecule interferometer, even to construct a variety of integrated molecule-optical elements and their molecule chips.
A new scheme to realize a two-dimensional (2D) array of magnetic micro-lenses for a cold atomic beam. formed by an array of square current-carrying wires, is proposed. We calculate the spatial distributions of the magnetic fields from the array of current-carrying wires and the magnetic focusing potential for cold rubidium atoms, and study the dynamic focusing processes of cold atoms passing through the mag- netic micro-lens array and its focusing properties by using Monte-Carlo simulations and trajectory tracing method. The result shows that the proposed micro-lens array can be used to focus effectively a cold atomic beam, even to load ultracold atoms or a BEC sample into a 2D optical lattice formed by blue detuned hollow beams.