Eur. Phys. J. D 1, 239-242 (1998)
https://doi.org/10.1007/s100530050088

Pulsed polarization gradient cooling in an optical dipole trap with a Laguerre-Gaussian laser beam

¹ Institute of Physics, University of Tokyo, 3-8-1 Komaba, Meguro-ku Tokyo 153, Japan
² Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku Yokohama 223, Japan

Corresponding author: ^a torii@phys3.c.u-tokyo.ac.jp

Received: 10 July 1997
Revised: 5 January 1998
Accepted: 16 January 1998
Published online: 15 March 1998

Abstract

We utilized a blue-detuned Laguerre-Gaussian (doughnut) laser beam to trap cold rubidium atoms by optical dipole force. "Pulsed" polarization gradient cooling was applied to the trapped atoms to suppress the trap loss due to heating caused by random photon scattering of the trapping light. In this trap about 10⁸ atoms were initially captured and the trap lifetime was 1.5 s, which was consistent with losses due to background gas collisions. This trap can readily be applied to atom guiding, compression, and evaporative cooling.