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 'pi'-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 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 'pi'-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 propose a novel scheme to form one- and two-dimensional arrays of double-well optical dipole traps for cold atoms (or molecules) by using an optical system composed of a binary π-phase grating and a lens illuminated by a plane light wave, and study the relationship between the maximum intensity Imax of each optical well (or the maximum trapping potential Umax for ^85Rb atoms) and the relative aperture β (= α/f) of the lens. We also calculate the intensity gradients of each optical well and their curvatures, and estimate the spontaneous photon-scattering rate of trapped atom in each well, including Rayleigh and Raman scattering rates. Our study shows that the proposed 1D and 2D arrays of double-well traps can be used to prepare 1D and 2D novel optical lattices with cold atoms (or molecules), or form an all-optically integrated atom optical chip, or even to realize an array of all-optical double-well atomic (or molecular) Bose-Einstein condensates by optical-potential evaporative cooling, and so on.
We propose a novel scheme to form one- and two-dimensional arrays of double-well optical dipole traps for cold atoms (or molecules) by using an optical system composed of a binary π-phase grating and a lens illuminated by a plane light wave, and study the relationship between the maximum intensity I max of each optical well (or the maximum trapping potential U max for 85 Rb atoms) and the relative aperture β ( = a / f ) of the lens. We also calculate the intensity gradients of each optical well and their curvatures, and estimate the spontaneous photon-scattering rate of trapped atom in each well, including Rayleigh and Raman scattering rates. Our study shows that the proposed 1D and 2D arrays of double-well traps can be used to prepare 1D and 2D novel optical lattices with cold atoms (or molecules), or form an all-optically integrated atom optical chip, or even to realize an array of all-optical double-well atomic (or molecular) Bose–Einstein condensates by optical-potential evaporative cooling, and so on.
We propose a novel, to our knowledge, scheme to form a controllable double-well optical dipole trap for cold atoms (or molecules) by using an optical system composed of a binary pi-phase plate and a lens illuminated by a plane light wave. We calculate the intensity distribution of the double-well trap and derive the analytical relationships between the characteristic parameters of the double-well trap (including geometric parameters, intensity distributions, and intensity gradients and their curvatures) and the relative aperture beta of the lens system. We also extend our controllable double-well trap to its trap array by using a binary pi-phase grating combined with an array of spherical microlenses. Our study shows that, if the pi-phase plate (or the pi-phase grating) is moved along the x direction, our double-well trap (or array of double-well ones) can continuously evolve to a single-well one (or an array of single-well ones) and vice versa, which can be used to study cold collisions between two atomic (or molecular) samples and atom interference with Bose-Einstein condensation (BEC) in a double-well potential; to prepare quantum entanglement between two macroscopic atomic assembles, even to realize an all-optical double-well atomic (molecular) BEC (including an array of all-optical double-well BECs) by using optical-potential evaporative cooling; to form a novel optical lattice with a larger lattice constant; and so on.
In this paper, we propose a new scheme to form an array of surface hollow optical micro-traps for cold atoms (or molecules) by using a phase grating with four phase steps and an array of microlens, study the intensity distribution of 2D array of surface hollow optical micro-traps, and calculate the corresponding optical potential for cold 85Rb atoms, and discuss some potential applications of our hollow micro-trap array in atom and molecule optics. Our study shows that when our grating-lens system is illuminated by YAG laser with a power of 1W, a 2D array of surface hollow optical traps with 104 micro-wells will be generated in an area of 1cm2. Each optical trap has some novel characteristics, such as smaller trapping volume, higher effective intensity and its intensity gradient. The corresponding optical potential for trapped 85Rb atoms can reach 190μK, which is high enough to trap cold atoms or cold molecules, and can be used to realize an all-optical atomic and molecular Bose-Einstein condensations, even to prepare novel optical lattices, and so on.
In this paper, we propose a novel scheme to produce a longitudinal controllable double-well optical dipole trap for cold atoms (or cold molecules), which is composed of a binary π-phase plate and a lens. The π-phase plate consists of two homocentric rings with equal area and opposite phase (0 and π), and its central region is opaque. When a plane light wave passes through the above optical system, a double-well optical trap will be formed at two sides of the focal point along the optical axis. The outer radius of the binary π-phase plate can be controlled by adjusting the radius of a diaphragm, so that a double-well optical trap will evolve and finally combined into a single-well, or vice versa. We briefly introduce the basic principle and derive several optimal parameters of the trap, and show the dependence of the optical parameters (including intensity distributions) on the geometrical parameters of the system. Our study shows that the proposed controllable optical trap can be used not only to trap cold atoms (or cold molecules) and realize all-optical, double-well or two species Bose-Einstein condensation (BEC), but also to study the trapped-atom (-molecule) interference, or form a 2D array of double-layer optical traps for cold atoms (or molecules), even to prepare a novel 2D optical lattice, and so on.
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.