We propose a novel scheme to build an all-optical surface atomic (or molecular) funnel using an optical system consisting of three cylindrical lenses, which can be used to produce a funnel-shaped intensity distribution near the focal plane of the last lens when the optical system is illuminated by a red-detuned Gaussian laser beam. We calculate the corresponding intensity distribution, the optical dipole potential and its dipole force for 23Na atoms. Our study shows that the proposed atom (or molecular) funnel can be used for the efficient loading of cold atoms in the surface optical guid, beam splitter and interferometer and surface microtrap, and so on. So our funnel has important applications in the integrated atom optics and its atom chip.
We propose a novel scheme to build an all-optical surface atomic (or molecular) funnel using an optical system consisting of three cylindrical lenses, which can be used to produce a funnel-shaped intensity distribution near the focal plane of the last lens when the optical system is illuminated by a red-detuned Gaussian laser beam. We calculate the corresponding intensity distribution, the optical dipole potential and its dipole force for 23Na atoms. Our study shows that the proposed atom (or molecular) funnel can be used for the efficient loading of cold atoms in the surface optical guid, beam splitter and interferometer and surface microtrap, and so on. So our funnel has important applications in the integrated atom optics and its atom chip.
We propose a new scheme to form a surface Y- or X-shaped beam splitter for optically wave-guided atoms (or molecules) and its Mach-Zehnder interferometer by using the combination of a binary π phase plate and a micro-cylindrical lens. The physics idea and basic principle of our beam splitter are introduced, and the analytic relationships between the intensity distribution (or the intensity gradient, or the splitting distance, and splitting-path width) and the parameters of our optical system are derived and discussed. The potential applications of the beam splitter and its experimental feasibility are discussed. Our study shows that the design is novel and the scheme is simple, and it can be used to construct various integrated atom- (or molecule-) optical elements with surface micro-structures, and even to form some all-optically integrated atom (or molecular) chips.
We propose a novel scheme to produce an array of micro-optical traps by using an optical system composed of a Damman grating and a spherical lens, which is illuminated by a red detuned Gaussian laser beam. We derive formulas to calculate the periodical structures of the micro-optical well arrays, and characteristics of each well, such as the spatial intensity distribution, intensity gradient, and geometrical parameters. Applications of our micro-optical traps in the fields of atom and molecule optics are briefly discussed. Our study shows that the proposed array of micro-optical wells can be used to trap cold atoms or cold molecules more efficiently than previous optical traps, even to prepare novel optical lattices.
A novel scheme was proposed to form the double-well optical trap by using shift phase gratings. A few pairs of adjustable double-well optical traps for trapping cold atoms or cold molecules were formed on the focal plane when the gratings were illuminated by plane light wave (or TEM00 mode Gaussian light wave) and focused by positive lens. The intensity distribution was calculated, and then the intensity distribution gradients as well as the analytical relations between geometrical parameters of the traps and the parameters of the optical system were derived. At the same time, three different evolution processes from double-well to unit-well were investigated. Also, optical dipole potential and photon scattering rate of the trapped cold atoms were calculated. The results show that the scheme not only is simple and convenient to realize, but also has wide application prospect in many fields, such as atomic physics, atomic optics, molecular optics and quantum optics.
An enhanced or improved far-field-diffracted optical dipole trap with a red or blue detuning for cold atoms or molecules on an optical chip is proposed, and our trap scheme is formed by an optical system composed of a binary phase plate and a circular aperture illuminated by a plane light wave. The relative radial and axial intensity distributions of the far-field optical trap and its optical potentials for 87Rb atoms are calculated, and the dependences of the relative intensity of the far-field optical trap and its well depth on the modulated phase φ of the phase plate are studied. Also, the feasibility of our enhanced far-field optical trap is analyzed, and some potential applications of our optical trap are briefly discussed. Our research shows that some geometric and optical parameters of the far-field optical trap can be greatly improved, and the evolution of the far-field optical trap from a red-detuned optical trap to a blue-detuned one can be realized by using our proposed binary phase plate. Particularly, with the change of the modulated phase φ from 0 to −π, the maximum intensity (i.e., the well depth) of the far-field optical trap and its trapping volume will be increased by about four and eight times, respectively. While the modulated phase φ of the phase plate is changed from 0 to π, a red-detuned optical trap will be evolved as a blue-detuned one, and the corresponding trapping intensity and volume will be enhanced by about 4 times. So such an enhanced far-field optical trap scheme has some important applications in the fields of laser cooling and trapping; atomic, molecular, and optical physics; integrated atom or molecule optics; quantum information science; and so on.
The basic principles of magnetic and optical atom funnels are introduced and the schemes and experimental results of various funnels are reviewed in some detail. These include optical funnels using a focused red-detuned Gaussian beam, blue-detuned evanescent-light wave and blue-detuned hollow beam, magnetic funnels with current-carrying wires, and certain magneto-optical funnels using magneto-optical molasses techniques. Finally, some potential applications of these funnels in atom optics are briefly described.
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.