Generation of one- or two-dimensional arrays of hollow optical microtraps for cold atoms, molecules, or microparticles on a chip

Abstract

We propose a new scheme to form 1D or 2D arrays of hollow optical microtraps for cold atoms, molecules, or microscopy particles on a chip by using an optical system composed of a four-step phase grating and a 2D array of microlenses. We calculate the intensity distribution of the 2D array of the hollow optical microtraps and its optical potential for 85Rb atoms and discuss its potential applications in atom and molecule optics. Our study shows that when our optical system is illuminated by a 1 W Ti:Sapphire laser, 103 hollow optical microtraps can be generated. Each optical microtrap has a small trapping volume and a high effective intensity, and its intensity gradient and the optical dipole potential for 85Rb atoms can reach 167 μK. Characteristic parameters of each optical microtrap can be changed by adjusting the parameters of our optical system, which can be used to satisfy real needs of various experiments to manipulate and control cold atoms, molecules, or microscopy particles.