All-optical trapping

Liya Chen, Jianping Yin

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.

Andrea Bulkley, Jason D. Forster, Debo Olaosebikan +1 more

Břetislav Friedrich

A detailed treatment of an electro-optical trap for polar molecules, realized by embedding an optical trap within a uniform electrostatic field, is presented and the trap's properties analyzed and discussed. The electro-optical trap offers significant advantages over an optical trap that include an increased trap depth and conversion of alignment of the trapped molecules to marked orientation. Tilting the polarization plane of the optical field with respect to the electrostatic field diminishes both the trap depth and orientation and lifts the degeneracy of the $\ifmmode\pm\else\textpm\fi{}M$ states of the trapped molecules. These and other features of the electro-optical trap are examined in terms of the eigenproperties of the polar and polarizable molecules subject to the combined permanent and induced electric dipole interactions at play.

Ch. Schneider, Martin Enderlein, Thomas M. Huber +1 more

Robert Pool

Zhengling Wang, Cao Guo-rong, Yin Jian-Ping +1 more

We propose a novel scheme to form a 2D surface array of optical micro-traps of cold atoms by using two sets of far red-detuned evanescent wave interference and a blue-detuned evanescent wave. The optical potentials of the 2D surface array of optical micro-traps are high enough to trap cold atoms released from the standard magneto-optical trap，and 87Rb atoms trapped in the array of optical micro-traps can be cooled to 2.56μK with efficient intensity-gradient Sisyphus cooling. Our study shows that the proposed 2D surface array of optical micro-traps can be used in atomic physics，atomic optics, quantum optics and so on.