Precision control of magneto-optically cooled rubidium atoms (Invited Paper)

Abstract

Research interest in designing sources of cold atoms has significantly increased during the past ten years with the development of suitable laser sources for magneto-optical trapping and the further mastering of evaporative cooling in order to achieve Bose-Einstein condensation. The magneto-optical trap is now viewed as a standard research facility worldwide and has opened up many new exciting research directions in atomic physics. One area of interest is that of combining spherical microcavities with cold atomic sources in order to achieve efficient photon exchange between the cavity and atom for further understandings of cavity quantum electrodynamics. This could eventually lead to atom entanglement via photon exchange which would have implications for quantum logic design. However, initial attempts to achieve such interactions have been hindered by inadequate control and manipulation of the cold atom source. Here, we present work on designing and building an ultra-stable source of magneto-optically cooled rubidium atoms with a temperature in the tens of K range. We discuss the different cooling mechanisms involved in the process and present a suitable experimental arrangement including details on the ultra-high vacuum chamber, the laser systems being used and the source of rubidium vapour. Finally, we discuss some future direction for the research including the diffraction of atoms from gratings and micron-sized objects and the parameter control of the cloud of atoms.

Sub-Doppler temperature measurements of laser-cooled atoms using optical nanofibres

“…The cold atom cloud is formed in a standard MOT configuration for 85 Rb [3,25], where three orthogonal counterpropagating cooling beams intersect at the centre of an inhomogeneous magnetic field. The cooling laser is locked to the crossover peak, 5 S 1/2 F g = 3 → 5 P 3/2 F e = (2, 4) co and then red-shifted by 12.4 MHz from the cooling transition using an acousto-optical modulator.…”