Berlin 2005 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
Q: Quantenoptik und Photonik
Q 32: Quantengase I
Q 32.1: Vortrag
Dienstag, 8. März 2005, 10:45–11:00, HU Kinosaal
Evaporative Cooling in an Optical Dipole Trap — •Anna-Lena Gehrmann1, Johanna Nes1, Tobias Müther1, Falk Scharnberg1,2, Wolfgang Ertmer1, and Gerhard Birkl1 — 1Institut für Quantenoptik, Universität Hannover, Welfengarten 1, D-30167 Hannover, Germany — 2Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
Cold ensembles and Bose-Einstein condensates (BEC) of rubidium atoms in optical dipole potentials have been studied by several groups in recent years. Most of the experiments using BECs rely on producing the condensate in a magnetic trap with subsequent transfer to the optical potential. Only a small number of groups have also succeeded in achieving quantum degeneracy directly in a dipole trap, predominantly by using the light of a CO2-laser.
In our approach, we use a solid-state laser which creates a far-detuned dipole trap for 87Rb at a wavelength of 1030 nm. This should reduce the complexity of the optical setup, and allows the use of ’more-standard’ optical materials and components. We aim at the creation of an all-optical BEC based on a simplified experimental scheme suitable for future generations of BEC setups without magnetic trapping fields.
We have successfully implemented first steps of evaporative cooling in our configuration. To achieve high initial phase-space densities allowing for efficient evaporative cooling, we have optimised the loading process from a magneto-optical trap. Furthermore, we have studied different timing schemes for the evaporation ramps. We report on the status of the experiment.