%0 Journal Article
%T Generation of Atomic Optical Lattices by Dammann Gratings
%A Xianming Ji
%A Shuwu Xu
%A Songbo Gu
%J Advances in Optical Technologies
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/647657
%X We first calculated the diffraction intensity distributions of the Dammann gratings illuminated by Gaussian light wave. The empirical equations were deduced by numerical calculations to calculate the parameters, such as the spatial period, the maximum intensity, and the maximum intensity gradient, of the optical trap array composed by a set of Dammann gratings and a focus lens. Thus, a novel type of optical trap array for trapping cold atoms (or molecules) was proposed and its features were discussed. The results showed the optical trap array with very short period could be generated. High optical dipole potential could be presented so as to have strong attractive force to the atoms to form atomic optical lattices of high lattice density. Compared with the optical lattices formed by standing wave interferences of CO2 laser, there are many unique advantages of which are formed by Dammann gratings. 1. Introduction In early 1970s, the concept of ¡°Dammann grating¡± was first proposed by Dammann and G£¿rtler [1] when they studied the copy of multiple imaging. The Dammann grating is a kind of phase-type grating with several groups of phase jump points in each period. The positions of the phase jump points can be computed by optimal designing. When the Dammann grating is illuminated by a coherent monochromatic light wave, many beams of diffraction light wave with equal intensity can be generated without the nonuniformity of beam intensity caused by sinc functions in common gratings. Many types [2¨C5] of Dammann gratings with high efficiency and large splitting ratio are developed in several decades to satisfy their applications. The orthogonal binary-phase gratings completing 64 ¡Á 64 splitting ratio have been successfully fabricated. Due to their advantages, such as the simplicity to be designed [6], the mature production process, and the easy calibration, they have been widely paid attentions to. In 1980s, Dammann grating was applied to the field of optical computing and optical interconnection. In 1990s, Tooley realized the image process of optical cells by using Dammann grating [7]. In recent years, a series of important developments and fruitful results have been obtained both in theory and in experiment on the cooling, trapping, and manipulating the neutral atoms (or molecules). As the deeply developing of the quantum information process and optical lattices [8¨C10], the surface microtrap array for trapping the cold atoms (or molecules) has become the research frontier in the field of atomic, molecular, and optical physics. Schemes of generating surface
%U http://www.hindawi.com/journals/aot/2012/647657/