Atom trapping and guiding with a subwavelength-diameter optical fiber

We suggest using an evanescent wave around a thin fiber to trap atoms. We show that the gradient force of a red-detuned evanescent-wave field in the fundamental mode of a silica fiber can balance the centrifugal force when the fiber diameter is about two times smaller than the wavelength of the light and the component of the angular momentum of the atoms along the fiber axis is in an appropriate range. As an example, the system should be realizable for Cesium atoms at a temperature of less than 0.29 mK using a silica fiber with a radius of 0.2 $\mu$m and a 1.3-$\mu$m-wavelength light with a power of about 27 mW.Comment: 5 pages, 5 figure

Atom Nanooptics Based on Photon Dots and Photon Holes

New types of light fields localized in nanometer-sized regions of space were suggested and analyzed. The possibility of using these nanolocalized fields in atom optics for atom focusing and localization is discussed

Magneto-Optical Trap for Thulium Atoms

Thulium atoms are trapped in a magneto-optical trap using a strong transition at 410 nm with a small branching ratio. We trap up to $7\times10^{4}$ atoms at a temperature of 0.8(2) mK after deceleration in a 40 cm long Zeeman slower. Optical leaks from the cooling cycle influence the lifetime of atoms in the MOT which varies between 0.3 -1.5 s in our experiments. The lower limit for the leaking rate from the upper cooling level is measured to be 22(6) s$^{-1}$. The repumping laser transferring the atomic population out of the F=3 hyperfine ground-state sublevel gives a 30% increase for the lifetime and the number of atoms in the trap.Comment: 4 pages, 6 figure

Guiding of cold atoms by a red-detuned laser beam of moderate power

We report measurements on the guiding of cold $^{87}$Rb atoms from a magneto-optical trap by a continuous light beam over a vertical distance of 6.5 mm. For moderate laser power ($<$85 mW) we are able to capture around 40% of the cold atoms. Although the guide is red-detuned, the optical scattering rate at this detuning ($\approx$70 GHz) is acceptably low. For lower detuning ($<$30 GHz) a larger fraction was guided but radiation pressure starts to push the atoms upward, effectively lowering the acceleration due to gravity. The measured guided fraction agrees well with an analytical model.Comment: final version, 6 pages, incl. 6 figure

Doppler cooling of gallium atoms: 2. Simulation in complex multilevel systems

This paper derives a general procedure for the numerical solution of the Lindblad equations that govern the coherences arising from multicoloured light interacting with a multilevel system. A systematic approach to finding the conservative and dissipative terms is derived and applied to the laser cooling of gallium. An improved numerical method is developed to solve the time-dependent master equation and results are presented for transient cooling processes. The method is significantly more robust, efficient and accurate than the standard method and can be applied to a broad range of atomic and molecular systems. Radiation pressure forces and the formation of dynamic dark-states are studied in the gallium isotope 66Ga.Comment: 15 pages, 8 figure